Terrible Performance on Mac?

Hi everybody, I'm testing the MPC Software demo on my Macbook Pro 14 (M1 Max) and I'm getting clicks & pops unless I raise the buffer size to 256, and even then I still get occasional dropouts...

This is a lot worse than the performance I get with other DAWs in the same computer where I can go down to 32 samples without any issues. The audio interface is a thunderbolt UAD Apollo X4 if that matters.

Anybody else having these problems?
Thanks!