Tilemap Dropdown doesn't update mouse over after flyout menu opened

Steps to Reproduce:

1. Create a new 2D project
2. Install the "2D Tilemap Editor" package from the Package Manager
3. In the Hierarchy Window, create a Tilemap via 2D Object > Tilemap > Rectangular
4. In the Scene View Overlays, click "Open Tile Palette"
5. Open the "Tilemap" dropdown in the Tile Palette window
6. Hover the mouse over Tilemap, then Create New Tilemap, then move the cursor outside the dropdown, and finally back over Tilemap again
7. Observe the highlight behaviour

Actual results: The mouse highlight becomes stuck on "Create New Tilemap"

Expected results:  The "Create New Tilemap" popup should close when the mouse leaves the area, and hovering back over Tilemap should work normally

Reproducible with versions: 1.0.0 (6000.0.1f1, 6000.0.45f1, 6000.1.0b15, 6000.2.0a9)

Not reproducible with versions: 1.0.0 (2022.3.60f1, 6000.0.0f1)

Tested on (OS): macOS 15.5