QFileSystemWatcher locks directories

I have a project which monitors all files and directories recursively from one root directory. This seems to work fine for files but not for directories. When I have a directory inside another directory, the top one can't be deleted because it's locked by my application.

Example:
Given the following tree, add root, base and leaf directories to watch, as well as file.txt.

root/
base/
leaf/
file.txt

Now deleting base is not permitted.

I see that there is this old bug report which is closed. Not sure what the resolution was. Perhaps the bug has re appeared or is slightly different.

https://bugreports.qt.io/browse/QTBUG-7905