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 had about 4 to 5 scouts who have said they RSVP for a different events in scoutbook but when our leader checked for final count they were not rsvp. Since this was different scouts and different events I need to open a ticket for assistance.
I’d suggest sitting down with them to watch what they are doing and immediately check the rsvp status. If still an issue here, please report back on anything odd you see.