Issues when activating Microsoft Learn Sandbox

Question

For the module: "Exercise - Explore the Learn sandbox", after completing the steps to activate the Sandbox, I keep on receiving this error message:

"Selected user account does not exist in tenant 'Microsoft Services' and cannot access the application '18fbca16-2224-45f6-85b0-f7bf2b39b3f3' in that tenant. The account needs to be added as an external user in the tenant first. Please use a different account."

I have already seen two other posts with people who have the same issue.

https://learn.microsoft.com/en-us/answers/questions/2151710/unable-to-activate-the-azure-learn-sandbox

https://learn.microsoft.com/en-us/answers/questions/2169167/problem-with-account-when-trying-to-sign-in-and-la

Seems that this is a systemic issue.

Would greatly appreciate your assistance.