As long as the they are listed in the agenda with a role that has the "The person assigned to this role can edit this agenda" checkbox checked, they should be fine. I do not see anything wrong with your agenda. Are you sure the members in question understand how to properly edit the agenda? Perhaps they just need some training... you can always refer them to the online docs here.
support.toastmastersclubs.org/doc/item/editing-an-agenda
