I created a form made by Toolset Forms and Toolset Forms Commerce (see attachment form1.jpg), it's a user form to let the existing customers upgrade to a VIP membership role, after filling in the custom user form and checkout, the user is able to get the VIP membership role but in the profile edit, the customer field data didn't update.
Sorry, there are some mistakes, now fixed. You can try login in again with the login password.
Here is how you can test the issue;
1. create a new customer account, go to the customer upgrade page.
2. randomly insert any text on the "Biographical Info" field, then submit the form and checkout.
3. the you can use the admin role that I provided to check the new acc profile.
Now I went ahead and test this for you and the field does in fact update i.e the Biological Info field. However the field only updates After I change the order status to completed.