Light not baking (2020.1)

Since Unity 2020.1 I've really big problems with baking lights. I've now spend over 7 hours and was able to bake only once(!!!). I don't think that the scene is any different to the one I've used when baking lights in 2019.3 because I have not added any static object to the scene.

It seems like that Unity just decides to stop processing the baking task (now at 39%. But I also had it at 83%, 99%).

Another problem is that Unity don't let me properly cancel/stop baking the lights. If I stop and start again then the other task must be somewhere in the background. I can see it because the panel Background Tasks get's a number within the brackets (which isn't the case if I run the task for the first time).

On top of that problem I have yet another one. When I want to close Unity after a backing process has failed - it stucks. So I have to foce-close it (which might related to the not closed background tasks).

Does anyone might have a workaround?