I updated to Android 10 on unlocked Note 10 plus today, and I was very surprised when I restarted and no keyboard popped up to let me type in my password on my start screen. Usually the Samsung Keyboard does, but it didn't this time, so I couldn't unlock the phone at all. I couldn't even restart since that requires a password. I had to use a dongle to connect a USB keyboard and type in the password. I tried rebooting hoping it was just a coincidence, but I experiened the same problem.
I did a factory reset, but still the same issue - unless I use the Samsung Keyboard, nothing pops up and I can't log in. This forces me to use Samsung Keyboard all the time. This definitely did not happen before the update.
Is anyone else getting this problem and figured out how to solve it?
I googled it with the keyboard I use (Fleksy) and it looks like they have a recent update, but it doesn't specifically address Android 10 and some other users were having the same problem. So I guess change your default keyboard back to Samsung if you use Fleksy keyboard before updating!