I have tried just now. But still can't see the button.
(as a side note, I am new to game-jams; how many little changes are we allowed to make to the game after submission? Or is this just an itch setting you needed to change?
You could consider adding a note to the game page on itch that people can try mobile if they encounter this issue. (by the way, I also do not understand the itch screen sizing thing... I had some issues with my game, but they seem to have disappeared somehow. I made my game in gameMaker and exported as GX.game instead of HTML. this solved the scaling issue for me.)