When you're on Android, using Chrome, many ads slip through.
On Firefox you'll notice these ads are filtered by PiHole.
Chrome uses it's own way to avoid ad blocking.
Use adb to tame Chrome like this:
adb uninstall --user 0 com.android.partnerbrowsercustomizations.chromeHomepage
It'll behave like expected afterwards.
O and btw
As I already mentioned in another post: vanced.app has a youtube app without ads.