I have two tables, Registration (child) containing student information, and Classes (parent) containing class information. The idea is to allow Everyone on the Internet to fill out the form to register for a class.

On the registration form is a dropdown box to select a class, which then displays lookup fields with data related to the class (date, location, etc, and Spaces_Remaining.) The Spaces_Remaining is calculated by taking a summary field from the Class Table grouped per class (Total_Enrolled) subtracted from a number field on the Class table that is the maximum number of allowed students (Max_Students).

All of the information displays perfectly, including Spaces_Remaining for the user roles of administrator and participant, and it updates properly upon changing the selection of the desired class in the dropdown. However, when I go to the form without being logged in to test it as a 'viewer', the spaces remaining field displays only the maximum number of students.

For some reason instead of calculating the formula, which is (Max_Students - Enrolled_Students), it only displays Max_Students. If I change the formula to be just ([Enrolled_Students]), it again displays properly for admins and participant, but for a viewer it shows 0. I've checked and re-checked permissions, and the viewer is given permission "view" to all of the relevant fields. The other lookup fields work perfectly for the viewer, but only this number formula field that is accessed via lookup field on the child table isn't working, and isn't working only for the viewer role.

Is there a buried permission setting I could be missing here, or am I missing something else? It's 99.5% working, so I think the setup is correct, but that lookup field just isn't calculating on the internet-facing version of the form, and am out of ideas, so any tips are greatly appreciated!