Hi NandiniBhagya,
Thanks for your message. I've had a look at that page. It says
"NewForm
The NewForm function changes the Form control's mode to FormMode.New. In this mode, the contents of the Form control's Item property are ignored, and the default values of the Form's DataSource property populate the form. If the SubmitForm function runs when the form is in this mode, a record is created, not changed."
when I look at the data card for the first field I see this as the default.

So is this why it shows a previous records info sometimes?
As an example, when I first open the screen directly using the > play button its blank. I fill in the details and then use my save button and it works. I then use the > play button again and it shows the first record in the SP list.
If I close the app designer, then reopen the app in the designer, and open the screen again, it again shows as blank.
Its like there is a bug in the designer.
Do you know whether in a new form I should really have the default set to nothing for all datacards?
I'm just thinking if this is a bug or if its because I have something in the Default function and if so, should it be blank for a form thats always going to be used set as New.
Thanks!