It’s for two factor auth tokens. When I fill in a password it copies my two factor code to the clipboard, then ~30 seconds later it restores the original clipboard content.

All pretty silly all things considered but I can’t think of an easier way to do things.

I wonder if it so they can restore the keyboard when you copy a password? I know they could copy it at time of copy as well but just a thought.

my guess is that it's checking to see if it can clear the clipboard or if you copied something else

The app does a check for URLs and will offer to open the URL using its own browser if it detects one.

Reading around it looks like there are better APIs for doing this, where you can ask iOS is the clipboard contains a string matching a pattern, which actually getting access to the content.