“Main” in SmartThings is a catch-all for convenience that will trigger with any button press, so that screenshot looks good (triggering button1 and main or button2 and main). Usually in routines you use button1 and button2, not main.
If sometimes the button does nothing when you press it, that’s a reliability issue as commented before and not driver related. Could be the firmware, bad repeaters, SmartThings issues, etc.