Mental Outlaw has a video about post YouTube Vanced. Basically: Kiwi browser + sponsor block + ublock + a violent monkey script to allow audio playback when your screen is off.
And honestly, it's been working great for over a year. I'd rate the overall experience as good if not actually better than Vanced tbh.
As has already been said, it's likely just an update issue - depending on your root status and whatnot, auto-updates unfortunately aren't much of a thing these days as far as I can tell.
Still, I rarely need to update, and only do so when something breaks (like when YouTube started killing playback when it detects adblocking recently).