Does the ball hang on your thumb when it pops?
The popping is do to a vacuum suction in the hole,
if it doesn't hang on your thumb i wouldn't worry
about it. That suction will allow you to relax your
thumb and not squeeze the ball resulting in a cleaner
release. The other option if it doesn't stick and you
don't like the pop take it to a pro shop and have them
put a vent hole for the thumb. This will allow the air
to escape from the hole as you put your thumb in.
