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.
When I sign in to scoutbook then go to Internet Advancement (Scoutbook plus) and view the calendar I see both my units and my subunits (Dens & Patrols). When I timeout, then log in to internet advancement directly, I no longer see my sub units on the calendar.
I then logout and login to scoutbook, go to Internet Advancement, and the calendar again shows my sub units.