I had this issue somewhat on my Samsung Galaxy S22 Ultra.
I think its an android bug/game bug. My game will be set to 40FPS with Vsync locked(not able to toggle on/off) if I try to raise or lower the setting it only goes lower. I found if I just do not apply this setting and cancel and go back in sometimes it will let me set to the max FPS of 120. Ive played this game recently on everything from a Steamdeck to desktop with Intel Arc GPu and only had this issues with android phones.
Wish I could be of more help. But its not just you, I would try what I recommended about moving the slider but not applying the settings then go back in and see if it will let you set to max FPS as default.