I use youtube across different devices with the same account. sometimes, i even use it in multiple browser profiles or apps on the same device (with the account logged in).
the ad reminder got me. it actually stopped serving any youtube video on my laptop. so i made a new profile in firefox, logged in, and it was fine. for a couple days.
so i made a new profile, logged in, and... was foiled. but not to be deterred, i did what any reasonable person would do: i sought out one of the DOZENS of alternative frontends and used youtube's recommendation algorithm on the main site to pull videos from the alternative frontend.
for one day.
today, on my laptop, with my old profile, never changing logins or browser settings, youtube started working again.
did we win?
I haven't even made any tweaks and it works perfectly for me.
Though yesterday it started triggering the "are you still watching" prompt within 15 minutes! The playlist had gone from an individual song to an hour long lofi mix I had in the background while doing laundry.