Grey shading in Scene view for Tilemap Focus On persists even after a Tilemap Grid is deleted

Steps to Repro:
1. create a new Tilemap in the Hierarchy
2. access the Tile Palette window so the Tilemap Focus On dropdown appears in the Scene View
3. set Focus On to Grid or Tilemap and the Scene View should have a grey shading
4. delete the Grid/Tilemap

Result: The grey shading from the Tilemap Focus On persists
Expected: The grey shading should disappear once the Grid/Tilemap is deleted

Note: The only way to get rid of the grey shading is to create another Tilemap and change the Tilemap Focus On setting back to None.