Unsolved Half my extension don't work on Linux Arch (Kernel 5.12.10, KDE 5)

[Mashallah]

To illustrate, I'll make a few screenshots of the reproduction in a new window.
First, I open a YouTube tab: https://i.imgur.com/llHbMay.png
There are no ads. If I right click -> Block Element..., it enters the element zapper mode as it should: https://puu.sh/HPFiw/384081559d.png
Then I right click on the tab above and clone it, and immediately see an ad in the top left as uBlock Origin stopped working: https://puu.sh/HPFiN/c2cc796247.png
Now right click -> Block Element... has no discernible effect - my input is just ignored and the element zapper mode is not entered (idk how to display this via screenshot).

Reloading tabs with F5 or Ctrl+R has no impact on their behaviour. Entering a different URL in the address bar of a broken-extension tab has the extensions keep being broken, suggesting this is a tab-scope issue.