I might be wrong but I think ad blocker warnings show up briefly after YouTube updates its detection methods. They vanish once filter lists catch up. It’s an ongoing cat-and-mouse game.
To reduce these warnings, update your ad blocker’s filter lists or they’ll eventually they do so automatically.
Update Filters: In uBlock Origin, open the dashboard, go to the “Filter lists” tab, and click “Update now.” Keeping uBlock itself updated helps too. Clearing cache can sometimes help. I think Firefox has better uBlock support, Chrome is toxic to adblocker integration.
Babe Ruth + Billy Ellish = Baby English