Bug (Case 1155777) "Open Scenes have been modified externally" pops up

It seems various operations in Unity mark the scene "dirty" and if I switch to another application and then back to Unity, the editor displays a "Open Scenes have been modified externally" dialog.

Spoiler: Video

Reproduce

• Open attached project
• Select "SampleScene"
• Assign "SampleScene" an AssetBundle name in the Inspector
• Switch to another application
• Switch back to Unity editor

Actual
Observe Unity displays an "Open Scenes have been modified externally" dialog.

Expected
Since the file wasn't modified externally, this dialog should not appear.

Note
Switching back to Unity, also causes my hard-drive to become very active for a short moment and the task-switch takes longer than in previous Unity versions. Maybe due to some new file detection stuff going on in 2019.3?!