When I tap on a line of text on my iPad (iOS 15.7.1), nothing happens. No cursor, so I cannot edit existing text or create new text. Desktop Mac and iPhone are fine. Searching, expanding a heading, sliding to delete/mark completed work fine.
You may have accidentally pushed the padlock on the top right of the screen which locked everything.
That’s probably what it was. I ended up re-installing. I didn’t realize there was a lock - it’s next to search which I often have to tap repeatedly (something with my screen, not the app). Thanks!