Just got hit with this for the first time, and at first I was like what the fuck is this happening here, I'm running Firefox latest, and UBlock origin latest, never seen this before. Happening for every video, two injected video ads before the video, seem skippable, but i'm not clicking on them. Hope UBlock catches up to this quick, this sucks.
Mine are getting trapped by pihole. They take 10 seconds to time out and just show a banner ad that won't automatically go away without hitting the skip button. It's really frustrating since I liked letting videos auto play as I fall asleep.
at least it's not currently spawning an actual video advertisement, so, small blessings, the two injected ads stay static for 10 seconds a piece (makes sense), and if you don't click skip, the first tiers to the second then tiers to the video (was thinking of going pihole but you just confirmed it won't make a difference, if they start injecting autoplay video ads, then it'll be back on my todo list)