Dragging any draggable query block makes the query block background invisible until hovering on it again

Steps to reproduce:

1.  Create a new project
2. Open Window > Search > New Window
3. Add any draggable search query block to the search field (e.g. Operators > AND)
4. Drag the query block to anywhere
5. Release the drag action so the query block goes to its starting position

Actual results: 
Query block background becomes missing until hovering on it again

Expected results:
Query block background stays visible

Reproducible with versions: 
6000.0.66f1, 6000.3.6f1, 6000.4.0b6, 6000.5.0a5

Tested on (OS): 
MacOS Sequoia 15.7.3
Windows 11