Yeah, small movements appear to be the bane of PETG. I have a print going right now at 30mm/s and there are four very small isolated supports that won’t stay put. Fortunately, they don’t appear to be critical (and I’m not even sure of their purpose), but with Snapmaker3D, there’s no option to remove them and there are places on the model that need supports. Two much larger support structures are printing fine.