On dragging Action Panel from UV Editor Window, highlights/select properties from the other windows which are in the background.

Steps to reproduce :
1. Create a new project.
2. Window > Package Manager > ProBuilder (4.1.2) > Install
3. Tools > ProBuilder > ProBuilder Window
4. ProBuilder >New shape (Cube is created in the scene.) > UV Editor
5. Click and Drag Action Panel over Cube Mesh.
6. Click on white Cube mesh and again click and Drag Action Panel over Cube Mesh.

Actual results:
While clicking and dragging the Action Panel, properties of another window are highlighted.

Expected results:
While clicking and dragging the Action Panel, properties of other window do not get highlighted.

Reproducible with:
2020.1.0a15, 2019.3.0f2

ProBuilder package version found :
4.1.2, 4.0.5, 4.0.2, 3.0.0

Environment:
macOS 10.15 and Windows 10.