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 a Den Leader that can’t get full access to his new scouts. He has six previous scouts that he has full access to but not with the new scouts. And yes, I have switched it to full access multiple times, it just never actually gets applied to those scouts.
@MichaelCasey the first issue is the person is not a registered leader and therefor it is a bug they are even a leader in Scoutbook. They need to send in an adult application and take YPT to be a leader. I searched by name and DOB and found no registrations