@samadril following to see you're successful returning to beta. I was unable to using the firmware update option. Maybe a 30-30-30 reset might work. 

So this issue reoccured for me today at the worst possible time with 4 people home either working or doing school remotely

so i figured if i was rebooting, might as well take the latest firmware

ive since rebooted and we'll see how stable it stays, but hoping it is resolved as this is annoying

Wanted to chime in here to say I have the 2.4Ghz issue as well. I am on the latest firmware (1.1.1). I have tried various different bands unsuccessfully. Just turned on smart connect to see if that works any better. Pretty disappointed since I specifically purchased this router in the hopes that it would be able to handle all my smart home devices.

@chaples55 did you try the beta firmware?

@shaywood 

No, not yet. I tried flashing it over 1.1.1 but it failed. Haven't tried the 30-30-30 reset that people are mentioning. I figured I'd give that a go if/when 2.4Ghz dies again.

Also having the problems again now that I've upgraded away from beta, seems like it is possible the beta fix never made it into the release channel. 

@Carl / @Tony - any insight here? This is discouraging situation given users here put down big bucks to get the flagship router, please help us out.

@Jerryb I did the latest firmware update, FACTORY reset the router, then manually (not using the backup file) re=entered all of the info.  So far, 4 days and no problems.  Not using SmartConnect.  I have about 6 devices on 2.4G and using all of the modes of it.

@Jerryb 

The latest firmware (1.1.1 Build 20200716 rel.84595(4555)) is simply awesome. Improved range, improved link rates with AX200 and older clients, and excellent reliability.