I found the corresponding place in the code:
Unfortunately, there is no comment indicating what the problem is.
There is an issue that deals with it, but also only speculates what the reason could be:
I have commented out lines 567-574 on a test basis and have not found any limitations so far.
I will run this for a bit and possibly make a pull request.
I am still open for explanations. Maybe I do something stupid or wrong.