Recently started using Forms, linking the fields in the forms to the custom fields we had been using, but the customer can no longer Show Details in the Portal at all.
Request type isn't blank and is filled in, the details are visible from the helpdesk view, it's purely the Portal view that the customer can't see the details of the ticket they have raised.
On Request Types where we aren't using forms, Show Details is still visible, as below.


Have tried reverting back but it's still missing.