My number already registered?

My account says it is already registered with a number but when I go to my DMs to talk to people it says I need to register a number. Well if it’s already registered why can’t I dm? I’m super confused. I’ve never DMed before so I’m not sure how to fix this.

Because someone who had your phone number before you registered it on tiktok. Only TikTok support can help

try to use another phone number on that account or the same phone number on different account an see how it goes just so that you can make sure.