I’m by no means an expert but have experienced something similar when cutting plywood with a 1/4" and 1/8" bit, using my SO3 and g-code output by Cut2D (Vectric).
My take is that the bit while under load (cutting), deflects. The direction depends on whether you’re inside/outside cutting and whether you’re using a conventional or climb cut.
So you have this bit (and the machine, too) that has deflected while cutting and all of a sudden it isn’t cutting, so I end up with some similar marks.
Using double-sided foam tape tends to worsen the symptoms for me, I think work holding is a contributing factor. Also, the bit deflects less when taking smaller bites, so for real important work I reduce my DOC and see a resulting reduction in that behavior.