Try turning off “markers follow edit” or update to PT23.12 at least . There was a huge bug in PT that they fixed in 23.12 I think that had nothing to do with MB. Pre 23.12 having that on will slow down everything massively even when manually cutting automation across empty segments of the timeline. So any PT version before that needs “markers follow edit” turned off otherwise every cut/copy/paste operation can take up to 30seconds
From the bug fix list of PT23.12
Improved editing speed when selecting across a lot of tracks with Marker Follows Edit enabled (PT-314515)