Turn Restricted Mode on or off on YouTube

Check the YouTube content restrictions page to see if you have any network or account level restrictions. A check mark will display beside the relevant restriction, and the text below will indicate the restriction level. If your DNS restrictions are on, and the level is set to “moderate” or “strict,” you have content filtering turned on.

https://support.google.com/youtube/answer/174084?hl=en&co=GENIE.Platform%3DDesktop