Why can't I access my Instagram account on the app using an iPhone?

Hi,

i can’t access any account on the Instagram app, i was recently banned and unbanned by the Meta. I contacted them they said from their end everything is fine, it could be an issue with the Phone.

i factory reseted my Phone, installed the app and still the same issue. The app loads but when i try to login it says that the account doesn’t exist.

However i can access the accounts though Safari or other iPhone there the app is installed.

Now i have a concern:

Since the apps are synced with Icloud is there a possibility if i change my iPhone and get a new one and use it with the same icloud account can i have the same issue there.

[Re-Titled by Moderator]