Steps to repro:
1. Create the new project;
2. Open the Project Settings window;
3. Select any item in the sidebar (i.e. HDRP)
4. With the sidebar item selected click on the resize area overlapping with selected blue item hightlight area;
5. Unpress the mouse button and move the cursor around

Actual result:
Window sidebar area is being resized even with the mouse button unpressed. See attached video.
Regression introduced in-between versions 2021.1 and 2022.2.

Expected result:
The sidebar is resized only when the mouse button is pressed.

Notes:
- Reproducible in Versions 2022.2.0a3, 2022.1.0b6, 2022.1.0b4;
- Not reproducible in Version 2020.3.26f1;
- The following warning is shown in Version 2022.1.0b4: Should not grab hot control with an active capture
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)
- The issue also happens in the other windows with resizeable sidebar (e.g. Preferences);
- The issue doesn't happen when clicking on grey area not overlapping with the blue highlighted area for selected items in the sidebar.