Sticky quarter hack

I have a problem with a few of my locations. It looks like someone is coating quarters in wax to be able to jam open the coin return area? Once that area is jammed, the coin mech drops the entire load of coins in the tubes.

I have no idea how it’s being done. I’ve blocked the buttons on the coin mech device that allows for coins to be dispersed, but it’s still happening. The only way for me to completely stop this, is to block the coin slot so it cannot be used.

It’s happening on BC-10s, 40 select snacks, chill centers, frozen machines, any machine.

No idea what to do here.