I found something, that makes perfect sense for me (but this is theory for now). In iOS 14 they introduced something called „privacy mac address”. It means, that every time you connect to the router...

@Kevin_Z By "investigating" you mean asking me questions via email that I already answered in this topic? And not answering to my questions how can I revert this crap router and get my money back?...

@Tudorct It's not working - tested. Same behavior, same version.

And believe me or not, but this must be software related. It's almost impossible, that so many routers are doing this in same moment.

They send me "beta" firmware - same version, different rel number and date from 04.2020. And what? Nothing has changed. Router restarted wifi few times and at the end of the day whole router...

Guys, I know this sounds stupid, but try disabling NTP & set date to few months ago. I'm testing something...