ZenWiFi BD4 nodes ignore 5GHz channel setting – always stuck on ch 36

[Cico75]

Hi, issue here with ZenWiFi BD4 nodes

I have the same channel sync problem but with the newer ZenWiFi BD4 (WiFi 7) nodes connected to a RT-AX88U Pro (Merlin 3006.102.7) via wired Ethernet backhaul.
Setup:

• Main router: RT-AX88U Pro (Merlin 3006.102.7)
• 2x ZenWiFi BD4 nodes – both wired backhaul (2.5G and 1G)
• BD4 firmware: 3.0.0.6.102_58138

Problem:No matter what 5 GHz channel I set on the main router (Auto or fixed – tried 36, 40, 44, 52, 60), both BD4 nodes always stay on channel 36. The router follows the setting correctly, but the nodes simply ignore it.

• DFS enabled/disabled → no effect
• Full power cycle of all devices → no effect
• Router Optimization button in ASUS app → non-functional
• BD4 nodes have no own web GUI, so no direct access

Result: Router on ch 60, nodes on ch 36 → massive interference and very unstable speeds (fluctuating between 5–470 Mbps).

Workaround: Fixed router to ch 36 to match nodes, but ch 36 is heavily congested here.

Has anyone found a solution for the BD4 specifically? ASUS support ticket has been submitted.
Regards

 

[Tech9]

Router on ch 60, nodes on ch 36

This is not normal for AiMesh. It uses all the same channels on all units. Must be some scanner app or WebUI glitch. You better use non-DFS range channels for reliability. How do you know Ch.42 (36-48) is heavily congested? You need available channel bandwidth data for this. The number of APs doesn't matter.

ZenWiFi BD4 (WiFi 7)

Wi-Fi 7 wannabe.

 

[degrub]

Hi, issue here with ZenWiFi BD4 nodes

I have the same channel sync problem but with the newer ZenWiFi BD4 (WiFi 7) nodes connected to a RT-AX88U Pro (Merlin 3006.102.7) via wired Ethernet backhaul.
Setup:

• Main router: RT-AX88U Pro (Merlin 3006.102.7)
• 2x ZenWiFi BD4 nodes – both wired backhaul (2.5G and 1G)
• BD4 firmware: 3.0.0.6.102_58138

Problem:No matter what 5 GHz channel I set on the main router (Auto or fixed – tried 36, 40, 44, 52, 60), both BD4 nodes always stay on channel 36. The router follows the setting correctly, but the nodes simply ignore it.

• DFS enabled/disabled → no effect
• Full power cycle of all devices → no effect
• Router Optimization button in ASUS app → non-functional
• BD4 nodes have no own web GUI, so no direct access

Result: Router on ch 60, nodes on ch 36 → massive interference and very unstable speeds (fluctuating between 5–470 Mbps).

Workaround: Fixed router to ch 36 to match nodes, but ch 36 is heavily congested here.

Has anyone found a solution for the BD4 specifically? ASUS support ticket has been submitted.
Regards

You may want to start over from a known good state to troubleshoot and clear out the NVram.

Factory reset, load the same code base firmware , if possible, to the main and the node units. Stick with the basic ASUS firmware for now. Manually config - don't load a saved config file. Use wifi 6 , turnoff wifi7 in the nodes. Set the backhaul to Auto. Add the nodes one by one. Let the AiMesh run for a day or so. Check the backhaul and 5 GHz channels after. Report back.

 

[Cico75]

Thanks for your reply!


I understand your point, but I don't think it's a scanner glitch. I ran multiple speedtests and the results were very unstable – fluctuating between 5 and 470 Mbps at the node location, which has a wired 2.5G backhaul. When I set the router to the same fixed channel as the nodes (ch 36), speeds stabilized.


I also checked with WiFi Analyzer AND the ASUS Router WebUI (Visible Networks) – both showed the same result: router on ch 52, nodes on ch 36.


Regarding the BD4 being a "Wi-Fi 7 wannabe" – fair point, it's entry-level WiFi 7. But it should still follow basic AiMesh channel sync, regardless of the hardware tier.


Any idea what could cause the nodes to not follow the router's channel setting?

---

Antwort an zweiten:


Thank you, that's really helpful advice! I'm actually considering doing exactly that – but I want to wait for the ASUS support response first, since I already have an open ticket.


One thing worth mentioning: I've had the RT-AX88U Pro for a while now and I'm not sure I ever did a proper factory reset on it. That could actually be part of the problem – accumulated NVRAM garbage over time.


Quick question before I start: would you recommend resetting only the main router, or the BD4 nodes as well? The nodes are relatively new, but I want to do it right if I'm going through the effort.


I'll report back once I hear from ASUS support or decide to go ahead with the reset!

This is not normal for AiMesh. It uses all the same channels on all units. Must be some scanner app or WebUI glitch. You better use non-DFS range channels for reliability. How do you know Ch.42 (36-48) is heavily congested? You need available channel bandwidth data for this. The number of APs doesn't matter.



Wi-Fi 7 wannabe.

Thanks for your reply!


I understand your point, but I don't think it's a scanner glitch. I ran multiple speedtests and the results were very unstable – fluctuating between 5 and 470 Mbps at the node location, which has a wired 2.5G backhaul. When I set the router to the same fixed channel as the nodes (ch 36), speeds stabilized.


I also checked with WiFi Analyzer AND the ASUS Router WebUI (Visible Networks) – both showed the same result: router on ch 52, nodes on ch 36.


Regarding the BD4 being a "Wi-Fi 7 wannabe" – fair point, it's entry-level WiFi 7. But it should still follow basic AiMesh channel sync, regardless of the hardware tier.


Any idea what could cause the nodes to not follow the router's channel setting?

 

[Cico75]

ups... something went wrong with the pasting... Sorry...

 

[degrub]

Thanks for your reply!


I understand your point, but I don't think it's a scanner glitch. I ran multiple speedtests and the results were very unstable – fluctuating between 5 and 470 Mbps at the node location, which has a wired 2.5G backhaul. When I set the router to the same fixed channel as the nodes (ch 36), speeds stabilized.


I also checked with WiFi Analyzer AND the ASUS Router WebUI (Visible Networks) – both showed the same result: router on ch 52, nodes on ch 36.


Regarding the BD4 being a "Wi-Fi 7 wannabe" – fair point, it's entry-level WiFi 7. But it should still follow basic AiMesh channel sync, regardless of the hardware tier.


Any idea what could cause the nodes to not follow the router's channel setting?

---

Antwort an zweiten:


Thank you, that's really helpful advice! I'm actually considering doing exactly that – but I want to wait for the ASUS support response first, since I already have an open ticket.


One thing worth mentioning: I've had the RT-AX88U Pro for a while now and I'm not sure I ever did a proper factory reset on it. That could actually be part of the problem – accumulated NVRAM garbage over time.


Quick question before I start: would you recommend resetting only the main router, or the BD4 nodes as well? The nodes are relatively new, but I want to do it right if I'm going through the effort.


I'll report back once I hear from ASUS support or decide to go ahead with the reset!

Thanks for your reply!


I understand your point, but I don't think it's a scanner glitch. I ran multiple speedtests and the results were very unstable – fluctuating between 5 and 470 Mbps at the node location, which has a wired 2.5G backhaul. When I set the router to the same fixed channel as the nodes (ch 36), speeds stabilized.


I also checked with WiFi Analyzer AND the ASUS Router WebUI (Visible Networks) – both showed the same result: router on ch 52, nodes on ch 36.


Regarding the BD4 being a "Wi-Fi 7 wannabe" – fair point, it's entry-level WiFi 7. But it should still follow basic AiMesh channel sync, regardless of the hardware tier.


Any idea what could cause the nodes to not follow the router's channel setting?

Go back to a clean known state on ALL of the devices.

 

[degrub]

ups... something went wrong with the pasting... Sorry...

Using Ai ?

 

[Cico75]

Using Ai ?

For Technical Translation it's easier, I am a SwissMen.

 

[Cico75]

Update – Factory Reset Test Results (NVRAM Clear)

After your advice, I performed a full factory reset (NVRAM wipe via GUI) on the RT-AX88U Pro to rule out any configuration issues.

Setup after clean reset:

• RT-AX88U Pro (Merlin 3006.102.7) – manually reconfigured from scratch, no saved config loaded
• ZenWiFi BD4 node – added fresh to AiMesh, wired Ethernet backhaul

Channel sync issue – still present after factory reset:

• Router: Auto channel → selected Ch 52/160MHz
• BD4 Node: Ch 36/160MHz
• Confirmed via ASUS Router WebUI (Netzwerkwerkzeuge → Visible Networks) AND WiFi Analyzer app – both tools show identical results

I guess it is a Firmware Bug.

At least the Performance ist better know. I will wait for the response of Asus Support and give them further information on the Test's i made.

 

[Tech9]

What you describe can only happen if your ZenWiFi BD4 set is in AiMesh in AP Mode configuration behind your RT-AX88U Pro router.

 

[degrub]

Update – Factory Reset Test Results (NVRAM Clear)

After your advice, I performed a full factory reset (NVRAM wipe via GUI) on the RT-AX88U Pro to rule out any configuration issues.

Setup after clean reset:

• RT-AX88U Pro (Merlin 3006.102.7) – manually reconfigured from scratch, no saved config loaded
• ZenWiFi BD4 node – added fresh to AiMesh, wired Ethernet backhaul

Channel sync issue – still present after factory reset:

• Router: Auto channel → selected Ch 52/160MHz
• BD4 Node: Ch 36/160MHz
• Confirmed via ASUS Router WebUI (Netzwerkwerkzeuge → Visible Networks) AND WiFi Analyzer app – both tools show identical results

I guess it is a Firmware Bug.

At least the Performance ist better know. I will wait for the response of Asus Support and give them further information on the Test's i made.

Are you able to factory reset the BD4 nodes as well ?

 

[Tech9]

This is a wrong configuration most likely due to paired BD4 units. I'm pretty sure the second unit uses the first one as master node. If the OP disconnects the cables the "mesh" will fall apart for this reason. The nodes have to be reset and added one by one to the RT-AX88U Pro making sure on AiMesh page the topology is correct. I remember playing with pair of XT8 units quite some time in order to achieve both units connected to different main node and not between each other. It's the dark side of ASUS attempts to make mesh sets more user-friendly. Sometimes the final result is the opposite.

 

[Cico75]

Are you able to factory reset the BD4 nodes as well ?

I performed a full factory reset on both BD4 nodes using the hardware method:

1. Power off the node
2. Hold the WPS button
3. Power on while keeping WPS button held
4. Wait until the LED starts flashing
5. Release the WPS button
6. Power off, then power back on
7. Re-added both nodes fresh to AiMesh

Unfortunately the channel sync issue persists even after this. The router selects Ch 52/160MHz while both nodes remain on Ch 36/160MHz. This confirms it is a firmware-level bug and not a configuration or hardware issue.

And you won't believe what ASUS support just told me...
After all this detailed testing and documentation, ASUS support responded that this is a "hardware defect" and told me to go back to the retailer for a warranty claim. They didn't even say which one is defect. all three at the same time?
Both nodes showing identical behavior, the issue being reported by multiple users on SNBForums, and behavior changing after a software/NVRAM reset – and they call it a hardware defect. I have pushed back and asked them to escalate to their firmware development team. Let's see what they say next.

 

[Cico75]

This is a wrong configuration most likely due to paired BD4 units. I'm pretty sure the second unit uses the first one as master node. If the OP disconnects the cables the "mesh" will fall apart for this reason. The nodes have to be reset and added one by one to the RT-AX88U Pro making sure on AiMesh page the topology is correct. I remember playing with pair of XT8 units quite some time in order to achieve both units connected to different main node and not between each other. It's the dark side of ASUS attempts to make mesh sets more user-friendly. Sometimes the final result is the opposite.

Thank you for this insight! I thought about this too.
I have been wondering about exactly this – whether I should set up each BD4 unit independently first in a separate network, explicitly configure it as an AiMesh node, and only then add it to my main network with the RT-AX88U Pro.
Have you discovered a special routine, to get it to work?

 

[Tech9]

Have you discovered a special routine, to get it to work?

Yes. It's kind of preventing the devices of a paired mesh set from seeing each other during the setup process. I set up wirelessly one node only, the other one was off. Then I powered off the added node, powered on the second one and set up. The I powered up both and they were correctly added as nodes to the main router. After making sure wireless AiMesh is up and running you can connect the Ethernet cables Router LAN to Node WAN. Leave the backhaul on Auto. If you have a switch in between it may make the procedure more complicated. Try the above with BD4, see what happens.

 

[Tech9]

One more detail - when adding nodes make sure your main router is up and running, reset the node, wait for it to boot up and try finding it on the main router quickly, like in next 10 seconds. I found it works best for node discovery process. Make sure WPS is enabled on your main router. I know folks recommend disabling it as it is security weakness, but it's used by AiMesh for node discovery and for eventual AiMesh recovery after backhaul disruption. I can't be sure for the latter since AiMesh is a black box, but from experience wireless AiMesh recovers quicker with WPS enabled.

 

[jksmurf]

Wait until the LED starts flashing

Apologies to jump in on a minor point but it’s for yourself plus anyone reading the steps and following them in future.

Your step 4 is generally

4. Release the WPS button after the power light is (turns, goes) off.

Offizieller Support | ASUS Deutschland

Das ASUS Support Center hilft Ihnen Treiber, Handbücher und Firmware-Versionen herunter zu laden. Hier finden Sie auch FAQs und Troubleshooting Hilfen

www.asus.com

Not sure why that link is to a German Asus site but it comes up in English for me anyway. The BD4 is listed in Method 2.

 

[Tech9]

Not sure why that link is to a German Asus

Does this for some time. Funny ASUS Support is currently not available in Germany due to some legal dispute.

 

[Poul Bak]

Wi-Fi 7 wannabe.

Oh, there's still hope for you then