This is pretty unnerving, especially when you want to type in a filename or rename a sample. I've tried it both on Android (Firefox on Android 11) and iOS (Firefox/reskinned Safari on iPadOS 15). I have not tried it with a physical keyboard, as I simply do not possess one :/
My wild guess is that this has to do with the UI being drawn on a canvas rather than being built with native HTML5 elements.