I'm using the Samsung keyboard and for some reason, it double taps buttons when I push once. It's hard to explain, but sometimes I'll push like a letter and it does it twice. It's not just the keyboard, this also happens with the home screen buttons. I'll press the back button once and it acts like I pressed it twice. Anyone else have this problem, or any insight as to what I happening? Note 20 Ulta, UI 3.1
If you do not have one, try factory resetting your phone.
If that still does not work, you might want to take it in for service, could be a faulty screen.
when you see the issue again, submit error report to Samsung Members right away. I think it's the keyboard app having issue with the connection to server. (just a guess).
is the keyboard updated to latest version?