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.
@TaraEschenfelder your Key 3 Delegate and therefore Unit Admin positions ended - that is likely the cause. The unit can give you the positions again to resolve it
This sounds like one or more of the Scouts may have an open Pack membership in Scoutbook. If you post the Scouting America Member IDs (no names) we can look.
I’m hoping this will resolve itself after the migration. There isn’t a huge rush to get these in so I’ll see if it resolves itself in a few days and if not, I’ll check back.