Dragging and selecting vertices/edges/faces in UV Editor doesn't work if mouseclick is released outside the UV Editor Window.
Refer to the attached Video.

Steps to Reproduce:
1. Create a New Project
2. Window > Package Manager > ProBuilder(Any) > Install
3. Tools > Probuilder Window > New Shape > UV Editor
4. Face Tool > Drag-select such that mouseclick is released outside UV Editor Window

Actual Result:
Selection box is drawn and persists after the click is released but objects are not selected until UV Editor is focussed again

Expected Result:
Selection box appears while dragging and selects the desired object(s) irrespective of mouse release position and/or focus

Occurring in:
2020.2.0b2, 2020.2.0a1, 2020.1.5f1, 2019.4.9f1, 2019.3.16f1, 2019.3.0a1

Working Fine in:
2019.2.21f1, 2018.4.27f1

Environment:
Windows 10 and macOS 10.15