My solution for he pop-up to be flickering is to TAP 3 TIMES as quick as possible at the option you want to set. For example, if you want to change the font setting and the pop-up option keep flickering, tap the font setting 3 times quickly 😂 it's a bit tricky, but that already my solution for the longest time I play itch.io Twine and never able to ask the author because I don't want to be hindrance due to my people pleasing tendency ¯\_(ツ)_/¯