Made a new tiktok account with my info, but it’s already part of someone else’s profile?

My partner decided to cave and make a tiktok account. When he signed up the profile already had name, videos , likes etc, assumably from the previous holder of his phone number. We’ve followed all the instructions to clear cache and other settings but all the previous likes, followers etc. (too much to do one by one manually).
I can’t see his updated profile name from my account, only this other person’s.
Has anyone navigated through this successfully? How does he just have a brand new TikTok account for himself?