Its hard for me to give an exact diagnoses without more context. I can include some general steps to help you diagnose the issue so you can fix it... My suspicion is that it could be helpful to identify what is the difference between these environments. Maybe the Data row limit in your app? maybe connectors or different permissions in different places
Verify the Relationship: Ensure that the One-to-Many relationship between Project and Opportunity Product is correctly set up in the Production environment, just like in the Sandbox.
Check Security Roles and Permissions: Sometimes, these issues can be related to permissions. Make sure that the users who are trying to view the subgrid have the necessary permissions to read Opportunity Product records.
Review the Subgrid Configuration: Double-check the subgrid configuration, especially the "Show related records" setting. Make sure it's set to display Opportunity records with the correct view.
Inspect the Data: Ensure that there are actually related Opportunity products for the Projects you are checking. If the data is different between Sandbox and Production, this could explain the discrepancy.
Clear Cache: Sometimes, caching issues can cause unexpected behavior in Dynamics 365. Try clearing the browser cache and reloading the page.
Check for Custom Code: If there's any custom code or plugins involved, make sure they are working as expected in the Production environment.
Examine Server Logs: If possible, check the server logs for any errors or warnings related to this functionality. This might provide more detailed information about what's going wrong.
Replicate in a Different Environment: If possible, try to replicate the exact setup in a different environment (e.g., a new Sandbox). This can help isolate whether the issue is specific to the Production environment.
