Weird issue with RT-AX86U - 2.5GB slower than 1GB WAN

[farif2]

I have a new RT-AX86U. I recently upgraded to 2.3GB line and my internet router (will call it router) has a 2.5GB port. I use RT-AX86U as my main router with its WAN connected to the 2.5GB LAN port of my internet router (and have disabled the WLAN for that). Issue is that when I use the 1GB LAN of the router to AX86, I get almost 950MB on the wireless. BUT if I connect the 2.5GB port to the 2.5GB port of the AX86U, I get 750MB max on same wireless. Doing the Internet speed testing from the menu within the AX86U gives me almost 2GB speed . BUT wireless of AX86U is not exceeding 750MB.
What can be the issue. Have done multiple hard resets and have used stock and latest merlin as well. Same repeatable speed. Have tried multiple channels but same. Its as if the ASUS router internal connection to the 2.5GB WAN is slower than the 1GB WAN. A fun thing that I tried that helped is to use DUAL WAN and then use failover to 1GB WA. In that case I get 1GB right away. Why would internal internet speed test of the AX86U see the 2.5GB speed and the wireless of the same router not see it?

Pulling my hair here

 

[Ripshod]

What speeds does a wired connection to the router give you? WiFi is so variable it's not a reliable test.

 

[farif2]

I don't have a Wired system to check router. But with wireless S23 Ultra connected to Internet router is 2GB speed. Same connected to Asus is 700mb. Plug the 2.5GB cable from the WAN to 1G WAN on the asus and making 1G the primary, I get 950MB speed on same S23 Ultra

 

[Tech9]

I don't see an issue. Your single mobile device testing provides limited and perhaps inaccurate results and the speed difference doesn't matter for this particular device. With this single 2.5GbE port router and all wireless devices you can never really use your >2Gbps plan, even for aggregate throughput. Don't overpay for ISP high speed plans.

 

[farif2]

Getting 950 and 750 CONSISTENTLY. So there is a difference and S23 Ultra is SAME. Not sure what do you mean speed differnce doesnt matter and we shouldnt pay. Its Euro 12 vs Euro 10.5 for 500mb. No brainer.

Repeated this multiples times as I had to reset and try again. I think the issue is the 2.5GB to Wifi link.

Anyone has >2GB link and GOT something close to it in Wireless?

 

[Tech9]

You can get about 1.7Gbps throughput to 2-stream client using 160MHz wide channels and only close to the router.

 

[bbunge]

Getting 950 and 750 CONSISTENTLY. So there is a difference and S23 Ultra is SAME. Not sure what do you mean speed differnce doesnt matter and we shouldnt pay. Its Euro 12 vs Euro 10.5 for 500mb. No brainer.

Repeated this multiples times as I had to reset and try again. I think the issue is the 2.5GB to Wifi link.

Anyone has >2GB link and GOT something close to it in Wireless?

Did you try another CAT5e cable, or better, between the modem and router?