A little more reliable way to reproduce this bug:
1. Open a new window (not maximized)
2. Start workspace switcher
3. Click once on the opened, non-maximized window [Workspace switcher closes]
4. Move mouse to the top/left/right edge of your screen
5. An orange grid overlay appears covering whole/left half/right half screen
A little more reliable way to reproduce this bug:
1. Open a new window (not maximized)
2. Start workspace switcher
3. Click once on the opened, non-maximized window [Workspace switcher closes]
4. Move mouse to the top/left/right edge of your screen
5. An orange grid overlay appears covering whole/left half/right half screen