Yeah, this is a big issue I’m struggling with on my iPad Mini 5 (latest iOS).
I don’t know if this will help to reproduce the issue, but when I’m simply tapping on the screen, the paste menu doesn’t appear. But if I type a couple of characters, then press enter to move to the new line, then select the characters and the next line, and then tap on the selection area - it works again. Like so:
Needless to say, this is an extremely frustrating issue. I really hope you guys can find a way to fix it.