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’ve had that happen when I’ve created a couple of events. Best way I can say to remedy the invites, when it does that do the following: scroll down until you see invitees. Click that tab and go in and select all the invitees you want to attend, broken down by leaders, parents, members, etc. Hope this helps, good luck!