My AX58U won't broadcast 5GHz WiFi on channels 116-128.

[Damun]

This morning i changed the 5GHz channel from 100 to 116 (less interference according to my WiFi analyzer app) on my 40 days old AX58U.
However, once i set it and applied i had no 5GHz WiFi - it couldn't be seen by either my phone or my other WiFi devices. I tested all channels from 100-140:
When using channels 116-128 (and sometimes 132) the router won't broadcast any 5GHz WiFi.

I am using stock firmware, v. 3.0.0.4.386_41700, recently updated. I have two AX58Us setup in AiMesh.
After the update i reset everything (hard reset using WPS button), reset from GUI and set everything up as described in M&M by L&LD.

According to my WiFi analyzer app there are no SSID's on any of the channels in this range.

What could be the cause for this odd behaviour?
Are these the channels used by AiMesh? Or is my router faulty?

I have set the channel back to 100 and I won't be able to test anything until this afternoon as my kids are using the internet for school.

 

[L&LD]

How long did you leave it there?

 

[thiggins]

You are trying to operate in DFS channels. Before any of these channels can be used, the AP must monitor the channel for 1 minute to see if it detects radar. If radar is detected, the router must immediately leave the channel (which drops all connected STAs) and not use that channel again for at least 30 minutes.

The 1 minute monitor period applies to ANY DFS channel. So if you keep moving from DFS channel to DFS channel, you are going to encounter the 1 minute delay each time.

Note that if you are using 80 MHz bandwidth, that uses 4 channels. All must be scanned for radar for 1 minute each.

SmallNetBuilder's Wi-Fi Dynamic Frequency Selection (DFS) FAQ - SmallNetBuilder

What is Dynamic Frequency Selection (DFS) and why should you care? Here's the straight poop.

www.smallnetbuilder.com

 

[Damun]

How long did you leave it there?

A minute or two. On other channels the SSID would appear on my WiFi analyzer within 30-60 seconds.

You are trying to operate in DFS channels. Before any of these channels can be used, the AP must monitor the channel for 1 minute to see if it detects radar. If radar is detected, the router must immediately leave the channel (which drops all connected STAs) and not use that channel again for at least 30 minutes.

The 1 minute monitor period applies to ANY DFS channel. So if you keep moving from DFS channel to DFS channel, you are going to encounter the 1 minute delay each time.

Note that if you are using 80 MHz bandwidth, that uses 4 channels. All must be scanned for radar for 1 minute each.

SmallNetBuilder's Wi-Fi Dynamic Frequency Selection (DFS) FAQ - SmallNetBuilder

What is Dynamic Frequency Selection (DFS) and why should you care? Here's the straight poop.

www.smallnetbuilder.com

Oh, ok. I didn't know that. Thanks for the link. You pointed me in the right direction.
Just to make sure that i understand: These channels are used by weather radars and other radars, so my router has to scan them for a while to check to verify if the channel is free of radar before using it and this may take a while.

 

[thiggins]

Oh, ok. I didn't know that. Thanks for the link. You pointed me in the right direction.
Just to make sure that i understand: These channels are used by weather radars and other radars, so my router has to scan them for a while to check to verify if the channel is free of radar before using it and this may take a while.

That is correct. That's why there are so few people using the channels.
Also, please don't try to use 160 MHz channels in DFS. You are just asking for headaches.

 

[ColinTaylor]

In the EU the wait time for DFS channels (52-144) is 1 minute. However, weather radar channels (120-128) incur a wait time of 10 minutes.

 

[Damun]

That is correct. That's why there are so few people using the channels.
Also, please don't try to use 160 MHz channels in DFS. You are just asking for headaches.

Great. Thanks. I'lle keep out of that range.

In the EU the wait time for DFS channels (52-144) is 1 minute. However, weather radar channels (120-128) incur a wait time of 10 minutes.

Thanks. This would explain why i didn't see anything popping up on the WiFi analyze. I was only waiting a minute or two.

Thanks for your help @thiggins and @ColinTaylor

 

[L&LD]

Any changes you make to the router and don't wait at least 5 to 15 minutes (and ideally, after a reboot), you're not really testing anything.

With the next-gen SoC's expected from the best/newest Wi-Fi 6E (true 3-Band, 3-Radio) routers, this may change.

But they will still need to be complying with local laws as @thiggins points out above.

 

[Damun]

Any changes you make to the router and don't wait at least 5 to 15 minutes (and ideally, after a reboot), you're not really testing anything.

With the next-gen SoC's expected from the best/newest Wi-Fi 6E (true 3-Band, 3-Radio) routers, this may change.

But they will still need to be complying with local laws as @thiggins points out above.

Well i was actually only waiting for the SSID to show up on my WiFi analyzer, which was 30-60 seconds for channels outside of the "probelmatic" range.
I'll keep in mind to be patient and wait for longer time in the future. Come to think of it, i think that i read that somewhere in your M&M or some of the other setup guides that you've made. Great work btw
Thanks @L&LD