It seems almost all TP-Link routers have 2.4 chipset degradation. Thanks to this thread I understood that I'm not alone in this sh1t situation and the support of the TP-Link is another bull sh1t. They can do nothing because of the hardware problem. The only thing they offer is the product replacing till the router on guarantee period.

The decision is simple - AVOID ANY TP-LINK products.

Probably you'll be happy with a new cool router, but after a while it become just a brick.

Have you guys tried rebooting from the firmware?

Mine had the same issue, and it didn't work when I off/on the router physically, but worked perfectly so far when I rebooted the modem through the firmware.

@Danize 

Hello - I have the same problem with the latest software (1.3.6 Build 20200902 rel.65591).

For now - I get soft for tests (1.3.1 Build 20200507 rel.34028(4555) - it is better - but sometimes I loose WIFI connection.

What can we do ?

Change the channel for wireless setting (2.4GHZ) 

go to Advanced menu

select Wireless Settings

select 2.4GHZ 

select Channel: from drop down menu --> set to 10 

and save.

Hopefully it will works.

Well, I am last to this forum and apparently not the first to the 2.4 GHZ issue.  And from everything I have read on-line, TP-LINK is not very good with their technical support or response, so pretty much left on your own, or with some guy named Kevin who works a couple of hours a day from his basement in a very remote location.  I live in Italy (not Italian) and have been using a TP-LINK modem/router on Telecom Italia ADSL/DSL for a number of years.  It is an older version, model TD-W8970 and only has the 2.4 GHZ and it has been very reliable.  I wanted to update/upgrade it to hopefully get a stronger signal throughout my house and bought the AC 1200 (model Archer VR 400) that has both the 2.4 GHZ and 5 GHZ.  I set up up and enabled both and even though the LED shows both the 2.4 and 5 GHZ on, none of my devices show the 2.4 GHZ.  So I messed around with it for about an hour, resetting, reconfiguring, rebooting, and finally I got the 2.4 GHZ to show up.  I had also purchased two AC 1200 WiFi extenders and paired them up.  All worked fine.  Unfortunately, after several weeks, the power went out in my building and I had to reset it.  This time I could not get the 2.4 GHZ to work, even though it shows that it is enabled and the LED shows that it is transmitting. So I figured that it was a defective unit, so I took it back to the NEX store and replaced it with another AC 1200 (model Archer VR 400). The box had been opened and the only one left, but the salesman told me I could bring it back if it does not work.  I believe these AC 1200's had been sitting there for a while and are older models no longer available at the NEX.  Anyway, I set up the new AC 1200 and the same issue.  Cannot get the 2.4 GHZ to work, even though it is enabled, the LED shows it is on, and the firmware is up to date.  I have reset, turned off and on, re-booted, and messed with it multiple times, can't get the 2.4 GHZ to work.  Maybe I should shake it or take a hammer to it?  The 5 GHZ works fine.  Any solutions for the 2.4 GHZ, or should I just take the two modem/routers and the two WiFi extenders back to the store and find another brand?  I don't think the TP Link technician Kevin who lives in the basement from some remote mountain top is actually set up to help. 

@Nap-Dav 

Hello! Kevin must be busy with the millions of topics and problems that people generate or actually have on a defective device. As for your problem, have you tried to set the channel and the frequency of the 2.4GHz network manually? Try to set the frequency to the maximum in terms of the channel, try several of them, it could be that your house or close to it has a lot of interference in the channel that the router has set automatically, which can cause devices not to find it.

I bought an Archer C80 just today and experienced the issue exactly as how most of you described it. I really can't understand why TP Link wasn't able to understand the issue fully considering that most of the people posted clear explanations of what we are experiencing. I will say to you already TP Link, the issue is real! Anyway let's go to the good part, I was able to make it work for now and I hope this is the permanent fix (cross fingers). Please try this to your devices as well and if it works too, then we have a workaround. Now TP Link should provide a permanent solution!!!

The workaround - the idea is to make the Channel Width different for 2.4 GHz and 5 GHz. Seems like these two doesn't work properly if set to "Auto". So I believe the issue is when both channels ends up 40 MHz.

1. Put your 2.4 GHz to 20 MHz.

2. Put your 5 GHz to 40 MHz.

If it works for you, please update this thread.

Correction

****So I believe the issue is when both channels ends up either 20 MHz or 40 MHz.

Another possible setup is to put 5 GHz to 80 MHz then leave 2.4 GHz to Auto.

Adding myself to the list of frustrated users... Just got a AX6000 2 days ago and experienced the 2.4G network drop like all others. 5 works fine, LAN works fine.   Going to try the recent suggestion above by putting the 5 network on 80HHz and leaving 2.4 on auto.