When input[type=password] is focused on iOS 14, the field appears to get focus but the software keyboard isn't opened and the onfocus event is not fired. On 4th gen iPad Safari just crashes. Minimum reproducible example here: https://jsfiddle.net/mt5j6o24/
I cannot reproduce this. Is this still happening for you with the latest beta? If you are observing a crash, could you please upload the crash log?
<rdar://problem/75829131>