Sony a7s III 4k/60

I just got the a7s3 and Premiere doesn't seem to like the files. I hope to get my ninja attached to it and resume shooting prores, but it's been hard to get stable on a gimbal without the HDMI pulling the camera out of wack.

I've got a decent machine, and the files scrub and edit fairly smoothly, my problem is when I change from scopes to effects controls, usually to make a slight rotation and bump up scale to cover the black gaps, it can take what feels like a solid minute for the rotation to apply, then another full minute for scopes to come back up and my playhead to scrub properly. After that I can grade pretty much fine and do other edits as I'm used to. Any idea why going to effects controls and back and making the pc chase it's tail?