Same issue here but with an Archer AX90. 2G is broadcasting and shows available to connect, but no devices are able to connect to it. Super frustrating when all of our smart devices (lights, plugs) require the 2G connection. 

The issue started yesterday out of nowhere. I seen an update was available and applied that which seemed to fix the issue for 1.5 hours. It works after rebooting the router but only temporarily. 

@Kevin_Z 

Smart Connect was already disabled, but I have since changed the settings per your recommendation to 802.11 a/n/ac mixed and rebooted. My 2.4G is back up and running for now but I'll update if the issue persists. 
 

@Kevin_Z 

Not even 10 minutes later and I'm once again unable to connect to the 2.4G network again. 

I think something else is going on other than the routers.  I say this because I had the exact same problem using Verizon's FiOS routers and it was the reason I returned mine (after trying multiple units) and brought out the Archer 1200 that I had bought a bunch of months ago.  I'd dreaded having to reassign IPs and reapply firewall rules, but I was at the point where it was happening 2-3 times a day, every couple of days.

So when I replaced the FiOS router, everything was good for a week or so and then BAM.  It started happening again.  Certainly with less frequency but still, it was happening exactly the same way.  And my solution was the same; disabling the 2ghz radio and waiting a few seconds, then enabling it again.  And the behavior was the same as with the FiOS router - I'd lose BOTH 2 and 5 gig links (despite ONLY TURNING OFF THE 2G RADIO) then everything would come back up a second later.  I wouldn't see it again for days or even weeks.  I just had to do it now, which is what prompted me to come here and make this post.

As I said, this is happening WAY less with the Archer than with the FiOS piece of junk and I have much better range with the Archer, eliminating the need for a booster (which I'd thought at one point might have been the cause, but today's episode happened a few days after I completely unplugged and removed the Wifi extender.  If anyone from TPLink wants me to answer any questions or supply data, feel free to ask.  But I'm starting to wonder if the problem is elsewhere in our networks and the routers are just reacting to it, cause it seems wierd to me that the problem/symptoms/solution remained the same for me across two VERY different routers.

Kevin_Z wrote

@rpitera 

 

Just want to confirm that if you are still using the Archer C6 router, or you are actually switching to Verizon's FiOS router now? 

I am using an Archer C1200 v.3. 

And I returned the FiOS router and am only using the Archer at this time.  Drop out happened again last night (about 8:00 PM local time) and took a number of reboots to even be able to access the router UI.  After a couple of recycles of the 2G radio, everything was back up and is stable at the time of this post.

Log is attached if it's of any use.  BTW, I've tried changing the channel and channel width (no change) and I am using a 802.11b/g/n mixed setting in case any of that info is of value.

  @Kevin_Z I am experiencing this with the Archer AX11000. Purchased 2 weeks ago and now the 2.4 drops but 5 ghz is still fine along with the hardwired drops. 

Turning off/on the 2.4 radio works, but doesn't last. Duration is sporadic. 

Suggestions? 

  @UPEagleEye 

Yes, I had a solution to the problem. Assign the channels manually for each router that way it doesn't stop working.
If you use channel 5 on the router, you should assign the same channel for all range extenders. Apparently If it is used in Auto it stops working. I can only give you my solution since it is the only one that has worked for me in years.

Sorry for the late response, I had lost my account password. I found this solution through a friend who works in computer networks.