DSF

I have a 120z latte sleeve in; the flower pot is same size as that mug without a handle. part way through the pressing there is a ping sound and the pot slides out. Anyone any ideas? Its happened twice now

The ping sound is a hairline crack in your ceramic. Reduce the pressure on the press.

thank you--would that cause the pot to pop out as well?

It probably doesn't fit properly or else it requires an exact placement in the press.