Error signing into BI account

I have a colleague who has a business account with my company, but is unable to log into Power BI. He receives the following error when signing in: "You have an account with us. You're using [email protected] with another Microsoft service already. To finish signing up for Microsoft Power BI, sign in with your existing password.

But when he attemps to sign in, he still cannot gain access.

I read a few similar posts from 2017 and 2018 but none of the solutions seemed to work - I had him try siging in with the following IDs: [email protected], [email protected], and [email protected] with no success. Has anyone experienced this before, or do you know how I can go about fixing this issue?