Steps to reproduce:

•  Import the attached "CustomThemeSelectorRuleIssue.unitypackage" into any project
• Select Test->StyleSheetButton-Editor menu to show an editor window
• Notice the red button and hover/click on it, it keeps its red background
• Open the "ButtonStyledTheme" scene
• Enter playmode
• Hover on all 3 buttons
•  

Actual results:  Not all buttons are red, especially when hovered

Expected results: All buttons should be red, when hovered and clicked.

Reproducible with versions: 

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS):  Windows editor

Notes:

• Something fishy is going on. Changing the PanelSettings of one of the UIDocuments in the scene might affect the styling on the other documents. My gut tells me the style cache might be to blame here