Extension: Still getting notification after disabling it in setting

I still get a notification for new videos, even though I disabled it in the extension' settings.

I'm on Firefox 70 on Elementary OS.

Reproduce the notification behavior in Firefox 70 on Elementary OS with new-video notifications disabled in the extension settings. Trace the extension's notification flow and settings handling; done means disabling the setting prevents further new-video notifications.

Written by the indexing model from the issue text.