Hi, I'm John! I will help you with this.
Microsoft Q&A is public, and we can only provide information. It is beyond our capability to assist directly with the account.
The limit you’re seeing is actually a security feature from Microsoft to help protect accounts from unusual or automated activity. Unfortunately, there isn’t a way to manually remove this restriction.
What you can do is wait for a full 24 hours before trying again. After that time has passed, you should be able to add the alias without any issues.