Welcome! This forum has a treasure trove of great info – Scouters helping Scouters! Just a heads up, though - all content, information, and opinions shared on this forum are those of the author, not the BSA.
I have an AoL Den Leader who has at least three MID’s. She can log into an old account, but not her current registration account. Please review these and tell me the next steps to help her.
@DougWright has the user tried to manage the numbers? log into my.scouting.org > Click Manage Member ID > one of the BSA # will be there marked PRIMARY > as long as the info is the same then add the other MID (BSA #) - you want to make the one that is your unit registration PRIMARY.