Hi @summitb ,
Could you please share a bit more about your scenario?
Do you want to display the Quick Create form when your add a record rather than redirect to the New Form?
Have you configured the form order for the Quick Create Form in your Entity or set the Quick Create Form as the default form of your Entity?
Actually, a form could be displayed as a Default form of a Entity is based on the Form Order you configured within your CDS Entity.
Please check the following article for more details:
https://docs.microsoft.com/en-us/powerapps/maker/model-driven-apps/create-design-forms#why-isnt-my-form-displayed-as-the-default-form-in-the-app
You can enable custom activity entities to support quick create forms, and you can create quick create forms for those entities. However, the quick create form for custom activity entities will not be used when people select Create on the navigation bar. These quick create forms can be used only when people add a new record for a sub-grid that displays that specific custom activity entity.
More details about creating a Quick Create Form for a Entity, please check the following article:
https://docs.microsoft.com/en-us/powerapps/maker/model-driven-apps/create-edit-quick-create-forms
Please check if you clicked the "+New" button from a lookup or sub-grid to create a record instead of clicking the "Create" button within the navigation bar.
If the issue still exists, please consider re-create your Model-Driven app, then re-create a new Quick Create Form based on above article, and add it within a Entity via a lookup or sub-grid, check if the issue is solved.
Best regards,