I don't know where you are running this code or how you are calling it, but I think the issue could be that you are creating multiple timers, maybe.
Anyway, this code worked for me. I added a
timer_required so the timer was only started once. I get a countdown. Not sure it's exactly what you want though.
t = Timer.new()
timer_required = false
axe_progress.value = t.time_left
axe_progress.visible = false