I have this same problem. Ever since I have upgraded to iOS 14.x both my iPad and iPhone are intermittently losing WiFi connections. And my wife’s Samsung phone at the same time works fine . I think this is definitely a bug in the iOS 14.x

I was having the same problem. Ever since I upgraded to 14.x the WiFi connection keeps on dropping intermittently. The WiFi signal stays shows full but actually was not able to browse internet niether could connect to the router GUI via WiFi. At the same time everything was working fine in my wife’s Samsung phone. That means the router and internet connection was ruled out. It was only the iOS 14 device both iPhone and iPad having issues. But then I upgraded my router and brought a dual band . So when I connect on 5Ghz band thr problem seems to have solved .