Apple ID E-Mail can't be changed

Hey all,

yesterday I just created my new iCloud E-Mail and can not change my Apple ID to my new E-Mail. I only get the warning that it is not possible to use the E-Mail at the moment.

When I change it on my iPhone with the latest iOS, it tells me the change was sucessful and then informs me I shall log in with my old E-Mail in the future, which means it didn't work either as it normally is a confirmation for the new E-Mail.

Has anyone had this issue before and is able to help?

Best Regards!