Custom panel app and portlet is not shown for non omniadmin users

Issue

• We have a custom module that puts a module in the product menu.
• We have a site role, S1, with permissions assigned to the module:
  • Access in Site and Asset Library Administration,
  • View.
• If we log in with:
  • an admin user, we can see the category and the module.
  • a regular user with a regular role with enough permissions, we can see the category and the module.
  • a regular user with site role S1, we cannot see the category nor the module under the product menu.

Environment

• Liferay DXP 7.4

Resolution

• This custom module has a PanelApp class. This PanelApp points to a PanelCategory via the OSGi component property "panel.category.key".
• The value of thsi property has to begin with the prefix "site_administration".
• In this example of the Liferay codebase, the value of "panel.category.key" is the constantPanelCategoryKeys.SITE_ADMINISTRATION_CONTENT, which is resolved to "site_administration.MyCustomPortlet", fulfilling the prefix requirement.