You already imported your invite list to the event, but still haven't set up the limit of how many additional guests they're allowed to bring to the event. You can easily fix this in two ways!
Reimport the list with the fixed count of additional guests per invitee
Change the number of "+ guests" in the invite list spreadsheet and reimport your invite list to the event again. During the import process make sure to choose the "overwrite" option to switch the existing list in the system with the new one you're importing.
โChange the number of + guests for all invitees in the system directly
If your list is long and you want to avoid the import process again, you can easily change invitees "Additional guests" limit in bulk. Just go to Invite List> Invitees, bulk select all invitees and choose the "Edit additional guests allowed" option in the "Actions" menu.