The other replies are incorrect, the lower tier premium actually has no ads on most videos. When you subscribe, they explicitly let you know music videos will play ads, probably so this plan is not eating away profits of YouTube music.

No, my system language is set to English. If it’s working like that for you, then there must be some misconfiguration on my part… But I never specified anything regarding languages.

I have custom formats in my profiles, and nowhere there did I see any option to prevent titles in multiple languages being searched. Could you please be more specific as to where exactly I can find that setting?