On Windows, if you touch the game screen while you’re riding, it gives you two buttons on the lower left - Quit Event and Menu. When you’re cycling, it’s easy for your finger to accidentally press the Quit Event button when you meant to press Menu.
Zwift, can you please move these buttons a little further apart?
Agree it could be better, but there’s a secondary confirmation check in the middle of the screen asking if you really want to quit so it’s not going to do any harm if you hit the wrong one.