Alex Pankratov :
Jul 27, 2020Not a known issue, no.
The "what to backup" file tree widget is being populated in real-time, but the directory scanning is done in the background, using as many threads as there are CPU cores. Not being able to control the thread count is an oversight and I will have this rectified in the next maintenance release.
Once folders are indexed they are added to the view and *this* is done by the same thread that handles the mouse input, so I'm guessing there's something laggy going on when populating the file tree with on-screen items.
There was a separate report for a similar issue - which was an extreme lag in rendering of the window contents - it too was on W10, but it was only triggered in a presence of Google Backup and Sync + Visual Studio + running a build in VS.
Would this apply to your case by any chance?