Page-specific $document exception causes ABP to stop working on entire website

Environment

• OS version: Windows 10
• Browser version: Chrome 94.0.4606.61 / Firefox 92.01.1
• Extension version: ABP 3.11.2
• Last working version: TBD

Steps to reproduce

1. Add the filter: @@https://www.youtube.com/watch?v=Zcf-OcvT03Y|$document
2. Go to https://www.youtube.com/watch?v=Zcf-OcvT03Y
3. Navigate to a different page without reloading (e.g. by clicking on YouTube's logo on the top-left, or another video)

Observed behavior

ABP remains disabled on other pages (ABP's icon remains Grey on Firefox, while on Chrome icon is Red)

Expected behavior

ABP should work on pages other than the one where it's disabled

Further information

• Same result when disabling ABP on a specific page using the toggle in the bubble UI
• ABP remains disabled while navigating the entire website, but starts to work again after reloading/refreshing
• DevTools/ABP panel may be needed to properly observe the issue
• See related fix in EWE that could be backported to adblockpluschrome