I have had a similar problem for a while now. Apparently there was an issue when my council uploaded their MBC list to Scoutbook some time back which ended my previous MBC position, but did not create a new one. Ever since they first uploaded the file, I’ve been in the same situation. Unfortunately, once the council uploads the list, they have sole control to get the list correctly uploaded. They can get support from some folks working with Scoutbook, but in the end, it’s essentially in their hands.
Have you been able to verify that your council has uploaded a MBC list? If you try to add a merit badge counselor position for yourself at My Dashboard -> My Account -> My Positions -> Add, does the system not allow you to add one? If not, then your council has uploaded the list and only they can straighten out the list issues.
Are you also a leader or parent in a unit? That’s what I believe the note is referring to. I’m a unit admin, and it says the same thing at the top of My Dashboard -> My Account -> My Connections