Every few seconds Unity slows down heavily, especially ‘scripts’ and ‘others’ which spike hard in the profiler, I thought it was garbage collection but it doesn’t look like it.

I checked the script usages and there is no significant (if any) change between how much scripts were being used - furthermore I put the game in a situation where it flatout did not instantiate anything and the framerate still got jerky from time to time.
ANy ideas what I should be looking for to fix this?