Hi @karimabdelrazek ,
Could you please share a bit more about your issue?
Do you mean that the LookUp field options list displays properly, but the selected option could not be displayed correctly in this field?
Have you tried to select other option in this LookUp field Dropdown box? Same issue?
Regarding the issue that you mentioned, I have made a test on my side, and don't have the issue that you mentioned. The screenshot as below:
When you select an option from a LookUp field in a Model-Driven app, the Primary Name field value of the selected LookUp field option (record value) would be displayed in the Dropdown box. So please check if the Primary Name field value of the selected LookUp field option is not Blank in the Related Entity (this LookUp field reference values from).
If the issue still exists, please consider edit the corresponding Entity form (used in your Model-Driven app) in your CDS, then remove the LookUp field, then save and publish the Entity form. Then edit the Entity form again, enable the LookUp field, save and re-publish, run your Model-Driven app, check if the issue is solved.
Also please make sure you have tied proper Entity form in your Model-Driven app. You could also consider create a new custom Entity form in your CDS Entity, then edit your Model-Driven app, bind the "Entity Form" part to your new created Entity form only, then check if the issue is fixed.
Regards,
