Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Greetings Bernard,
Hope you are doing well!
Once again thanks for detailed information, no, do not delete your personal email address. kindly open any office apps and try to sign in again check if it makes any difference.
If the Issue persist, kindly provide the screenshot of error you are getting (please hide your information) and at the same time Kindly contact the IT admins in your organization they will help you to perform the troubleshooting which are mentioned in above article because can only be performed by a Microsoft 365 admin.
Please feel free to let us know how it goes, I will keep assisting you based on the information you provide. We sincerely appreciate your patience and cooperation.
Thanks for your precious time.
Have a nice day!
Best regards,
Inema | Microsoft Community Moderator