Update January 11, 2021: I was informed about a better solution via Twitter, and updated the Blog post accordingly.
The Problem
During my personal tests with FSLogix 2009 (2.9.7621.30127) I discovered that the profiles won’t logoff completely at the end of the day. See the following screenshots.
You can clearly see, that despite there are no active or disconnected user sessions, some of the VHDX disks are still mounted, but more important the folders from C:\users\ won’t vanish.
This makes a second login impossible on the same VDA.