Can't run correctly on Firefox since the MV3 update

[Katzenwerfer]

The only way to have it working is to give permission to run on all sites and restarting the browser.
After that, it works correctly until you open and close the popup, which seems to stop the background script altogether without running it again until the browser is restarted.

[fengffang]

How exactly should it work? How do I actively grant it permission to run on all sites?