Error With Choosing Username For Business

I am a social media manager. My boss had a temporary TikTok with no followers or activity before I was hired. He just wanted to have the username.

When I was hired, he said he would d elete the account so I can set everything up on my end. But after this happened, I got the error message, "Couldn't update username. Try another."

I figured it might take time for TikTok to purge the old account completely, but it's been over 48 hours now and I'm still getting this error message. Does anyone know how long it takes before I can take that username over?