RT-AC86U reboot looping w/slot #1 5G guest network enabled

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New Around Here
I have an RT-AC86U running Merlin 386.1_2 and I am wondering if anyone else is having problems or if there are any known problems relating to Wi-Fi when the guest network is enabled in slot #1 (leftmost) - particularly the 5G guest slot? I know that during the stock 386 beta testing there were all kinds of problems with slot #1 so I am suspecting there might be?

Right now - if I enable my slot #1 5G guest network, my router goes into a reboot loop. This is the culmination of weeks of problems beginning when I upgraded to 386.*. At first it was infrequent disconnects that were easy to blame on the cheap IoT devices but after a while it got more frequent and effected more devices (though it seemed it was only 2G devices, although that's really the bulk of what I have). Reboots help - for like 12 hours. A few weeks ago the first reboot loop happened after making a minor change (I don't recall what) - I had to factory reset to get back up. After a couple weeks of more frequent disconnects - finally another reboot loop happened Friday night after I initiated a reboot to fix these ongoing issues. I lost faith and replaced the 86U with an old RT-AC68U that had been a secondary AiMesh node but that I promoted to be my primary. Things were flawless over the weekend including an XT8 joined as a secondary AiMesh node - and yes - a 2G and 5G enabled guest network with all the clients reliably connected and no issues.

Meanwhile over the weekend I booted the troubled 86U with no network cables or antennas (that I purposely hadn't factory reset so that I could troubleshoot with) and it magically seemed stable... so I went to swap it back in tonight as my primary and instantly upon reconnecting the cables and antennas the reboot loop ensued. I factory reset - again - and all was well again -- until I enabled the 5G Guest network on slot #1 and then the reboot loop happened again. I managed to get in there to disable the guest networks and it stabilized - then I went back to it an hour later, enabling the guest network on slot #2 - and I maintained stability. Oddly enough no one connected to the 2G network (and that is very odd, I may have typed the wrong SSID/password - but I don't think so). Two devices managed to connect to the 5G network according to the router anyway. Undeterred I disabled slot #2 and re-enabled slot #1 - expecting the 2G network to cause the reboot loop ... but it didn't - the 5G network did and does now if I enable it.

So right now I am running with the troubled 86U and slot #1 2G guest network enabled but 5G disabled. I have no reboot loop at the moment but I don't know whether devices will stop dropping tomorrow (oh geez, there goes one of my IP cameras now - grrr - now it's back a minute later ... and a minute after that two other IP cameras lose connection, these are all 2G devices on my main-not-guest Wi-Fi network).

So I'm having all kinds of issues. I feel like it's probably firmware ... but it could be hardware too? I'm looking for advice before I drop more $$ on a replacement.



P.S. At the end of writing this I upgraded to 386.2_beta2 and it seems all the symptoms are present - especially the reboot loop with 5G slot #1 guest network enabled. I'm also beginning to suspect the hardware at this point. :/


Asuswrt-Merlin dev
I have an RT-AC86U running Merlin 386.1_2 and I am wondering if anyone else is having problems or if there are any known problems relating to Wi-Fi when the guest network is enabled in slot #1 (leftmost) - particularly the 5G guest slot?
Yes, this has been extensively discussed on the forums. Use Guest Network 2 instead.


New Around Here
So I am still struggling with this problem - or rather these problems.

#1 - Reboot loop
  • I believe this person also had the problem.
  • I am wondering if this is a separate problem - unrelated to my second problem.
  • If it weren't for the above person having the same issue I'd just assume my router is dying and the reboot loop is a symptom but that's harder to do with another person experiencing it and with it seeming to be introduced with the 386 code base.
#2 - 2.4G devices drop off the network
  • Believe it or not but I bought an RT-AX86U and with it I was able to discern that 386_42095 seems to fix that problem for the AX86U.
    • I ran for 24 hours with Merlin 386.1_2 and had drops; then flashed to stock 386_42095 and ran without drops for 24 hours).
  • The only way to get my RT-AC86U to that code base is with Merlin's 386_2_beta2? Is this correct? Am I benefiting from the 42095 code base on this router even without Asus having released it for this router yet?
    • Because I am having drops still.
      • Although it is possible/probable that the drops are explained by a lack of AiMesh nodes + distance & obstacles.
Anyway, the AX86U seems to be doing better - although that's not proven with Merlin code - yet (and I need Merlin code for two things : VPN Policy Rules (and BTW why hasn't Asus adopted this awesomeness yet?) and Namecheap DDNS registration). I'd be happy to keep the AX86U - but only if my AC86U is failing. If it's firmware ... I think I'd rather go back to 384 until a fix comes along, I can't justify spending $250 on a software bug. To that end - I have a case open with Asus. The first person said they never heard of these problems before - bah. It's been escalated - we'll see where it gets - I just filled out a feedback form and submitted feedback/logs via the web UI.

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