Hello,ddmhm
Welcome to the Microsoft community!
I have realized that there are some issues with your Microsoft 365 subscription.
Before that, I would like to ask you for some information to better address your question.
I would like to confirm that whether you current account is a personal or business accounts? I'd like to confirm what the domain name is after the @, if the domain name is corporate it may be an anomaly to log in.
Considering you are using a MAC computer and logging in the problem occurs.
I suggest you try the license removal tool.
I suggest you use Office license removal tool to renew your license.
Log out of all accounts before running the tool.
- Download the license removal tool.
- Open the pkg file in your Mac's Downloads folder.
3. Select Continue and follow the prompts in the setup wizard.
- If you want to start removing the licenses, select Install. You may need to enter the password for your Mac's local administrator account.
When the licensing tool is complete, select Close.
- Now open an Office app and sign in to activate with the email account associated with your Microsoft 365 for Mac license. If you're working on troubleshooting, you might need to reinstall Office before you sign in.
Once you have activated the product, restart the computer and you can get back to work.
For more information, please visit this website: How to remove Office license files on a Mac - Microsoft Support.
If the tool doesn't work, I suggest can try to change the alias.
Add or remove an email alias in Outlook.com - Microsoft Support
Add an alias (live.com)
You can try changing to a personal email address if you have an enterprise domain email address, then switch to the primary alias, then use the license removal tool, and finally try logging in again.
If these don't work, then I suggest you contact Microsoft support to check your account authorization issues. Because of the account issues involved, forum counseling is not recommended for your privacy and security. I will help you to move to the right place.
Contact Microsoft Support.
(Monday to Friday: 9 a.m. - 6 p.m., Saturday and Sunday: 10 a.m. - 6 p.m.)
- Go to the following website: Contact - Microsoft Support
- Enter a contact there.
- Select Get Help.
- Select Contact Support.
- Under Products & services, select Microsoft 365 & Office.
- Under Categories, select Manage my subscription.
- Go to Confirm.
- Select Chat with a support agent or request a callback.
If you need more help, don't hesitate to send back.
Please understand that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
Feel free to post back if you need further assistance.
Thank you for your understanding and patience and I look forward to hearing from you.
Ryan - MSFT | Microsoft Community Support Specialist