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.

@shaywood I was unable to downgrade via GUI like most. I dod just restore my config after a factory reset of the router. Lost all my 2.4G again today and seeing if that does anything. I will try and update should it drop the 2.4 band again or other issue. I will also post should I figure out how to go back to the old firmware. All honesty I bought at Costco and if TP Link cant fix this I may return it. This should be something they are taking seriously and fix ASAP. Love the router but I expect my internet to stay stable especially when using tons of smart-home tech.

@Mystiky .. looking forward to see if that works and its just a matter of re-entering things manually. Please keep us all posted.

Well it worked great for a few days but I've lost all my 2.4 devices again 3 times in 2 days now. That's with smart connect on and firmware version 1.1.1. So looks like turning on smart connect is not the answer.

@chaples55 , yea I had where all the sudden I could not reach things from PC bit could ping from diagnostics on router. I have now set in the reboot section scheduled weekly reboot. That is really nice and worst case will eliminate the problem until its resolved in future code. We need TP link. To fix those though. I never had the problem in the beta code and wish I was still on it, but this code for its enhancements is also great outside the total 2.4 Loss.

Right now I'm set to once a week in the AM and will see if that stays stable sence the last factory reset. The backup, factory reset and restore definitly made it take longer before issues. I never did drop my 2.4 completely, just things stopped being reachable on and off and had to reboot which fixed it.

A temp work around for anyone with this issue and annoyance. You can at least schedule reboots as often as needed or never hopefully see the issue.

STILL NEED TO TRY: I still need to factory reset and manually put back in all info. Just not up for it right now as it will be very time consuming.

@Jerryb Still no problems here,  Been running the latest FIRMWARE since 9/21/2020 with no Router resets.