Contacts

I just got a new iPhone and it was working great..... but when I get a text message or call from people the contact name is not showing up just the number. I was on the phone with customer service and he said he has never seen this before, and there was nothing he could do. He didn’t know how to fix it. I googled it and it seems common with the iPhone. But it’s super frustrating. I tried to go to I cloud and toggle contacts on and off and resetting phone and it is still doing it. It’s super frustrating. Does anyone know how I can fix this problem.