RT-AX88U 5 ghz WiFi problems

[ItsMeDude]

Just bought a brand new RT-AX88U. Got through the initial setup and immediately upgraded to Merlin 384.9_0. Didn’t change any of the settings but was trying to find the 5 ghz WiFi on several devices that definitely support 5 ghz. Although the router indicated it was broadcasting, no device could see it. I factory reset the router and tried again, still no 5 ghz. I switched over to the Asus firmware 3.0.0.4.384.5640. 5 ghz immediately started working. Must be some sort of bug in Merlin. Thought posting here would help bring it to the attention of Eric. Should be easy to replicate considering it was factory setup without any changes to the settings on the Merlin firmware.

I had the same issue when I first upgraded. If I manually set the 5ghz channel to 161 or lower everything works fine. That's even with the AX framework enabled. If I set it to 165 it will disappear. I'm guessing that on auto that it's setting it to 165 because it's completely vacant of other APs. I scanned the channels and just forced them to the least used on both bands. I uploaded a screen shot. With it set like this it has been rock solid. I'm on 384.11.2

I hope this helps!

 

[Fifth313ment]

Try just using the defaults. Don't enter anything you don't know.

What is your 'Connect to DNS Server automatically' set to? Set it to 'No' and then enter the DNS servers you want to use.

I've had Asus routers for years and I setup IPV6 DNS cloudflare before but I have everything set correctly but it's not working. So I think it's a bug with the AX88 Merlin (or Asus OG) firmware. I also wanted to use the DNS over tls but I wasnt sure what to put as that was recently added to the firmware.

 

[Tenshi]

Is that an AX88U only issue ?
Since I have the AX88U , i'm struggling with the latest Merlin FW on 5Ghz
It wont appear. Sometimes by changing the settings on Wifi, i can't even access the router, but internet works fine
A reboot must be performed
I'm almost thinking to send that thing back

 

[Tenshi]

Hmm well, by enabling auto channel, AX support, 160Mhz, it works (for now). strange

update: it goes down again after some time. Issue still there

update: Issue is probably due the setup up which is not supported (not sure if due Merlin or not)
Ax88U (With latest Merlin FW) Ai Mesh\AP router => Ac88U (StockAsus FW)

5Ghz on the AX will go off once the AC88U is on.

 

[gamesman]

I also have a problem with my 5ghz wifi on my AX88U. running merlin 384.12. and the problem started to day. i have been running the FW for many days without problem. i tried what other said on previlus post but not working here

5ghz is on channel 0

10min witout power on unit and problem solved

 

[bcoz]

Same problem, NO 5GHz Wi-Fi.

Brand new RT-AX88U updated to Merlin 384.12 and the 5GHz Wi-Fi failed to work (5GHz LED was OFF, and band was not visible to PC or mobile). 2.4GHz band worked OK.
I tried turning '802.11ax HE Frame Support' to OFF, but it made no difference.

I updated to the latest Asus stock firmware (3.0.0.4.384.6210) and 5GHz Wi-Fi started working again.

I then updated to Merlin 384.13 Beta 1 and the 5GHz Wi-Fi disappeared again, same symptoms as for 384.12 above. I also created 2.4GHz and 5GHz Guest Wi-Fi networks as a test, but only the 2.4GHz Guest was visible.

So I used @Tenshi's suggestions and the 5GHz Wi-Fi started working again (both native and guest SSIDs):
https://www.snbforums.com/threads/rt-ax88u-5-ghz-wifi-problems.55088/page-3#post-503494
https://www.snbforums.com/attachments/screenshot_20190709-185456_chrome-jpg.18581/

Summary of workaround:
802.11ax HE frame support: [Enable]
Channel bandwidth: [20/40/80/160 MHz] and [x] Enable 160 MHz
Control Channel: [Auto] and [x] Auto select channel including DFS channels

 

[Bamsefar]

After 31 days of rock solid performance on my new AX88, my two Samsung Tab 10.5S starts to drop 5 GHz wifi and reconnects once every minute or so... I was runnig HE disabled, 80MHz and fixed channel. Now trying the oposit so HE enabled, 160MHz and auto, and it works again... very strange... oh by the way 384_12. This drives me nuts.

 

[RMerlin]

After 31 days of rock solid performance on my new AX88, my two Samsung Tab 10.5S starts to drop 5 GHz wifi and reconnects once every minute or so... I was runnig HE disabled, 80MHz and fixed channel. Now trying the oposit so HE enabled, 160MHz and auto, and it works again... very strange... oh by the way 384_12. This drives me nuts.

Try 384.13, it's based on a newer Broadcom SDK.

 

[bcoz]

I then updated to Merlin 384.13 Beta 1 and the 5GHz Wi-Fi disappeared again, same symptoms as for 384.12 above.

I just updated to 384.13 and the 5GHz Wi-Fi failed to work again, using default settings (5GHz LED was OFF, and band was not visible to multiple devices).

So I went with my previous workaround above.
An alternative workaround is to manually select a 5GHz channel, and leave 'Auto select channel including DFS channels' unticked.

 

[jwortiz]

Same problem, NO 5GHz Wi-Fi.

Brand new RT-AX88U updated to Merlin 384.12 and the 5GHz Wi-Fi failed to work (5GHz LED was OFF, and band was not visible to PC or mobile). 2.4GHz band worked OK.
I tried turning '802.11ax HE Frame Support' to OFF, but it made no difference.

I updated to the latest Asus stock firmware (3.0.0.4.384.6210) and 5GHz Wi-Fi started working again.

I then updated to Merlin 384.13 Beta 1 and the 5GHz Wi-Fi disappeared again, same symptoms as for 384.12 above. I also created 2.4GHz and 5GHz Guest Wi-Fi networks as a test, but only the 2.4GHz Guest was visible.

So I used @Tenshi's suggestions and the 5GHz Wi-Fi started working again (both native and guest SSIDs):
https://www.snbforums.com/threads/rt-ax88u-5-ghz-wifi-problems.55088/page-3#post-503494
https://www.snbforums.com/attachments/screenshot_20190709-185456_chrome-jpg.18581/

Summary of workaround:
802.11ax HE frame support: [Enable]
Channel bandwidth: [20/40/80/160 MHz] and [x] Enable 160 MHz
Control Channel: [Auto] and [x] Auto select channel including DFS channels

Have you also checked your NIC/driver settings? I recently bought the Dell XPS 7590 OLED laptop (VERY NICE BY THE WAY!) and I was having the same issue with the built-in AX Killer WiFi radio. Upon further investigation, I enabled the above settings on the router AND ALSO on my laptop NIC (see attached). It's been connecting without dropping since I've done this a few days ago. Hope this helps.

I'm running Merlin 384.13.

 

[bcoz]

Have you also checked your NIC/driver settings?

I have an older Intel Wireless-AC 8260 NIC that support AC only, and yes it is set to Dual Band a/b/g and ac.

 

[jwortiz]

I have an older Intel Wireless-AC 8260 NIC that support AC only, and yes it is set to Dual Band a/b/g and ac.

Sorry for the late reply, but life happened. Hopefully, you got this resolved by now. If not, knowing that you have an older NIC, check the Asus RT-AX88U settings (on the left): Advanced Settings > Wireless > General tab > 5GHz drop-down selection. I'd recommend "802.11ax HE frame support" is disabled along with unchecking the "Enable 160 MHz" and "Auto select channel including DFS channels" check boxes. See if that helps.

Oh, one more thing! In the Professional tab for 5GHz, make sure "Universal Beamforming" is disabled.

Hope this helps!

 

[bcoz]

Hopefully, you got this resolved by now.

Actually it's been working for over 3 months using the workaround noted in my previous comment:
https://www.snbforums.com/threads/rt-ax88u-5-ghz-wifi-problems.55088/page-3#post-506693

The original problem was that with the DEFAULT Merlin settings, the 5GHz band was invisible and its LED was turned off.

An alternative workaround (used my other posters in this thread) is to manually select a 5GHz channel, and leave 'Auto select channel including DFS channels' unticked.

I'm happy to leave my settings as is.

 

[RAH-66]

@bcoz use manual channel 149-161 (whithout DFS and TPC), in Australia this channel have most powerfull - 251mW
https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_(802.11a/h/j/n/ac/ax)
https://www.legislation.gov.au/Details/F2015L01438

 

[Jordan Housewright]

So I know I am a little late to the game but I found out today that I was running into the 5GHz channel 0 issue.

I work in tech so I SSH into the router and had a look at the sys.log and was happy to find that it never deletes so it had logs from the first day I booted the router. This allowed me to search what it looks like when the 2g band turns on and compare that to what it looks like when the 5g band was turned on. The sad thing is that I have had this since March and found out today that 5g never turned on!!!! I know I know what kind of a tech guy am I if I never realized this. I am kicking myself already about it.

But the good news is I was able to find a fix and it is simple and sounds dumb but I have tested it and I was able to reproduce the issue.

The fix for the 5GHz channel 0 is simply to turn off the router and unplug everything from it than turn it on. After you can see that both the 5G band and 2G band lights are on you are good to plug everything back into the router. Hope this helps others as this was the first form to pop up while I was searching google.

 

[L&LD]

@Jordan Housewright Welcome to the forums and thanks for taking the time to join and post that.

Fyi; what you discovered is part of my 'Nuclear Reset' which you can read about by following the link in my signature below.

 

[Rturnock]

No, the option is still there:

View attachment 16306

Same problem the box was not checked but my RT-AX88U disabled 5GHz. I manually selected a non-DFS channel and my 5G came back on.