I’ve upgraded Unity from 2019.2 to the recommended version 2019.4.4 LTS and I’ve noticed a significant increment in load times for my scenes (specially for one of them).
I haven’t changed anything in the project beyond this upgrade, so I guess it has something to do with the Editor itself.
I’ve profiled the Editor (with deep profiling enabled) and this is the result when it’s loading the scene:
Ok, I still don’t know what the problem is, but we unpacked the prefabs that were loaded in the scene (some of these prefabs were overriding the original ones) and the load of the scene is now instantaneous. Something was clearly off with the prefabs, but I don’t know what.