V12.1.8 Customer Portal: Customer unable to submit Issue

Hi everyone, we have a customer who couldn’t submit an Issue in the customer portal as shown in the picture below.

What we did? We added a field called “Quotation Required Date” in Issue doctype via Customize Form. We also added “Quotation Required Date” and “Issue Type” fields in the Issue web form.

We couldn’t figure out the cause of the permission problem as we have also set the permission for Customer role:

Submitted this issue in github: https://github.com/frappe/erpnext/issues/19472

How did you add new field in the portal?