Within a Power Apps environment, a table has been created with some custom columns as well. Then data has been created and added to the table within the Power Apps GUI. When adding a record, only the Primary name column is available for data entry.
After choosing the Table, then choosing the Data tab, and then Edit Record, only the Primary name column is available to edit. Other columns have been defined but are not presented on the new or edit record screens.
Is it possible to edit all fields in a Dataverse record using the Power Apps GUI?
Try adding the custom fields to a custom form. Use that form to edit the data.