0 and then 14.0.1 on iPhone 8.
I initially noticed this on 14.0 with Safari, when forwarding a URL to an email using the "action (share)" icon. Keyboard often didn't initially appear for input into the "To:" address field, but by moving cursor down to the subject or email body area, it then does, and I can move it back up to "To:" with the keyboard remaining visible/functional.
Yesterday, I tried to move 2 apps into a new home screen folder, and I coudn't see a keyboard to name the folder. If I hit lower part of the screen area, characters in the folder name would appear, but couldn't see control it. I had to soft reset the phone and then it was OK to create and name the folder.