Mental Outlaw defines Youtube's illegal and documented attack on Firefox videos

[SwordfishMining]

Are you trying to use an ad blocker to keep your time your own? Google's Youtube has it in the script to disrupt your feed and force it to keep reloading if you are blocking the ads, which is illegal under EU law and probably already headed to court for Google to lose and pay damages.
You can use a agent switcher or custom filter for U block origin like he says to make Google, who made this script, think you are using Chrome which it is pushing that prevents blocking its ads.