Unity Editor freezes after exiting playmode

I’m working on a VR-project with VRTK and SteamVR (on Windows). In this project, I use one scene for the scene layout (only static objects) and another one for the logic. That means, I have these 2 scenes loaded additively (which was no problem so far).

Now I have this issue from Unity 2019.2.7 onward:

Whenever I exit playmode, the Editor freezes for a significant amount of time (tens of seconds up to minutes sometimes). All click-actions on the Editor objects take extremely long for a couple of minutes after each playmode.

I have checked with the Profiler and Task Manager and found that there seem to be memory leaks (at least the memory usage is slightly higher than normally after playmode, even though that shouldn’t be enough to stop Unity). In the profiler window, I noticed that the “GC allocated” category in the memory-section seems to cause more spikes than before in 2019.2.6. Also, the Garbage Collector seems to be taking up much more space in the CPU usage field than before.

I’ve checked the release notes of 2019.2.7, but couldn’t find anything that would explain this issue. I have to admit that I’m not an expert on memory and gc, so I might have missed something.

In order to be able to work on my project, I’ve downgraded it to 2019.2.6. for now, but it would be helpful in the long run to find out what causes this. I’d be thankful for your input!

Still having this issue with Unity 2019.3.9, but sadly no solution :(.

Having this issue too. Running 2019.2, 2019.3, 2020.1 versions at iMac (21.5-inch, Late 2013). On other machines don’t have this issue. Moreover 2020.1 is freshly installed a week ago and a face the same issue.