Hi @Mattw112IG ,
Do you want to use a new form to create a new record in sharepoint list?
Firstly, you need to set the form's DefaultMode to : New.
Secondly, you need to connect your app to your list, set the item's data source to this list.
Thirdly, after you submit the form, what's the next action that you want?
If you still want to create another new item in this screen, I suggest you set the submit button's OnSelect:
SubmitForm(Form4);ResetForm(Form4);NewForm(Form4)
//submit the form, clean the data in the form and set the form's mode to new again
If all these settings are right, but you still can not update data successfully, then the problem should be about your settings of the form.
If so, please tell me:
1)whether you have required fields in your list
If yes, you need to use this field in your form.
2)the field's data type in your sharepoint list
3)the controls' settings and the datacards' Update in your form?
Especially the fields that you've customized.
Best regards,