The users can open the Invoice record, which proves that object and record access are already sufficient to reach the record. The fact that only a small set of system fields is visible while the administrator sees the full detail strongly indicates a Field-Level Security difference. If the Sales Users profile lacks visibility to the remaining fields, Salesforce suppresses those fields even though the page layout contains them. A page layout marked Read-Only would still display the fields; it would only prevent editing. A role-based sharing rule also cannot grant field visibility because sharing rules operate at the record level. The correct troubleshooting path is therefore to review the Invoice object ' s field permissions for the affected profile and any assigned permission sets, using Field Accessibility where useful to understand the effective result. The scenario reinforces that object permission, record sharing, and Field-Level Security are separate controls and must be diagnosed independently. Study Guide reference: Permissions to Standard Objects, Custom Objects, and Fields - Field-Level Security, field accessibility, profiles, permission sets, and separation of field security from record sharing.