Hi Eddie,
Greetings from the Syncfusion support.
We checked the your query with provided information and you customized the edit operation so we need additional information about your requirement and please share the below to us that will help to validate further.
- Share the complete Grid rendering and customization(bind external dialog while click on gray background text) of editing
- If possible to share the sample with your requirement
- Ensure that change value in dialog will reflect respect cell value in Grid.
Regards,
Balaji Sekar.