my iphone does not let me to change the mail and password. the Ipad did and the computer is fine

Had to change the mail address. so I did it in the Ipad, the computer and it is working , but on the iPhone 14 plus it does not allow me to change it. tried to enter my previous data but it is not working. in the appleid apple.com I removed my iphone , did not help.

what else can I do to reconnect with the new mail and password?