Hi Edwin,
No, it is not. The form sharing was correct. It was shared with a View permission with a particular group. In the meantime, I found the issue.
Issue & Solution:
When a custom form with section breaks has a Program as an object type it's associated with, then all users that need to use that custom form in a request queue to create a request, must have Manage sharing permissions to the request queue project. Otherwise, they are not able to see the custom form fields in the sections defined by the section breaks, based on the fact that the section breaks have a setting of Users with this access to the object can edit field values: Edit vs. Limited Edit. The Program object type removes the Limited Edit option and keeps the Edit only. The latter does not allow users (Contributors, Standard, etc.) to see and edit the form unless they have a Manage sharing permission on the request queue project. That doesn't help at all, if we need to have multiple Contributors and even Standard users creating requests. Also, Contributors are not allowed to have any Manage sharing permission based on their access level.
All in all, we had to remove the Program object type from the custom form and keep only Project and Issue. Then, we got back the Limited Edit option for each section break in Users with this access to the object can edit field values: Limited Edit. Also, we kept the sharing permissions for all Contributors and Standard users equal to View for the request queue project.
Advantage:
All users can see and edit the custom form with multiple section breaks.
Disadvantage:
The custom form in question cannot be shared with a Program. Only we can transfer the custom form data from Issue to Project.
