I have recently upgraded my mobile to samsung s24 ultra. I kept my old s21 ultra, with the idea to use that for personal and my new s24 ultra for business.

I had whats app business, installed on my old mobile, to my old mobile number. I have since ordered a new sim card, which I wanted to put in my old phone, to create a work free sim/number to use for personal, away from my work.

I factory reset my s21 ultra, and when trying to register whats app, it allows me through, as soon as I send one message, it immediately blocks the phone, saying the account is not allowed to use whats app due to spam (chats are still on this device)

TLDR - Error is the account is not allowed to use whats app due to spam (chats are still on this device)

Despite factory reset, how to i permanently delete my old chats from old sim/number so I can use whats app on new sim/number as hoped?

Thank you for reading and hope to have a fix soon