@gently Thanks for this, this is not just our own phone but on commercial machines. Yesterday my wife was buying train tickets so we could take her to Hospital for a CT Scan, she touched both hands, nothing so had to use her thumb this worked in the end. It happened on a car park pay station last week at Hospital again, every machine, I often end up doing it as none of her digits work work. I will adjust the phone though so thanks for this. Jon

I hadn't thought about a capacitive stylus
To successfully operate an unresponsive public touchscreen, you need a passive capacitive stylus with a wide contact surface or a precision disc tip. Public kiosks, ATMs, and airport check-in screens typically use thick, tempered glass or heavy-duty capacitive panels that require a larger surface area or highly concentrated conductivity to mimic a finger press.
I don't know if these work well or at all.
Top Stylus Options for Public TouchscreensDEWALT Stylus Pen 3-in-1$14.99Home Depot& more4.3(7)