Unable to View Generic List Items while Filling a Form
Issue

Resolution 1
You need to check the form form configuration. Now check whether the list is configured to the form field or not. To check this, we need to edit the form. Refer Edit a Form to modify the form.

Once you know the list spec, then you need to map the list items to the users who are not able to view them. Refer Map List Items to an Employee
Resolution 2
If all the employees or the majority are facing the same issue, then you need to enable the Offline Availability function where different sync modes are available. If you enable this setting, it impacts all the employees. Check out the Enable Offline Usage page for the procedure to enable the offline availability.
