Slowness when displaying large diff

Hi folks,
I have a situation, on latest instance of GitLab, where if I want to load a webpage with slightly larger diffs it will take 30-40s to load the said page, sometimes up to a minute. I’ve seen that only one cpu core goes to 100% leaving others unused.

Is anyone else experiencing this issue? I am aware there were issues with large diffs on 8.x but I cannot find anything referencing it on 9.x.

Is there a way to work around this?