Hi @raddy,
Could you please share a screenshot of your app's configuration?
Do you want to retain the fields used in the previous submitted form when you add a new form within your app?
I agree with @tchin-nin's thought almost, I have made a test on my side, please take a try with the following workaround:

I assume that I want to retain the Address field value used in previous form when I add a new form within my app. Please take a try with the following workaround:
Set the OnSuccess property of the Edit form control (EditForm1) to following formula:
Set(PreviousFormData,EditForm1.LastSubmit)
Note: The EditForm1 represents the Edit form control within my app.
Set the Default property of the Address Data card control to following formula:
If(EditForm1.Mode=FormMode.New,PreviousFormData.Address,ThisItem.Address)
Or
Set the Default property of the Text input control included within the Address Data card to following formula:
If(EditForm1.Mode=FormMode.New,PreviousFormData.Address,ThisItem.Address)
On your side, you should type the following formula within the Default property of the control:
If(EditForm1.Mode=FormMode.New,PreviousFormData.propertyName,ThisItem.propertyName)
The GIF image as below:
Best regards,
Kris