the keyboard went missing ... finally got it back
I'm using a Samsung S21 Ultra (Android 12, One UI 4.0) and as I was signing into a new app account the screen locked and the keyboard vanished.
I rebooted the phone, no change. I'm also now receiving a message that Google stopped working. After a little thinking, I went to Settings / Apps / Google and pressed on Force Stop.
That brought back the keyboard, which is a step forward, but it was the Samsung keyboard.
Long story short, it would seem there was a very recent update to the MS SwiftKey Beta that I'm guessing installed at the same time I was attempting to register a new app. (This was a legitimate app, the IMDb app.)
For good measure, I uninstalled SwiftKey Beta and reinstalled it.
Everything seems to be in order but for 15 minutes I was a little nervous. :)