Forms fail to submit from Issue Forms where the Summary field is hidden for the Request Type

Issue Summary

In cases where a Jira Service Management Form is set to create a new issue via a link to the form and does not have a form field linked to the Jira Summary field, form creation will fail when the associated Request Type has the issue Summary field hidden.

Steps to Reproduce

1. Set the Summary field on a Request Type's Request form page to hidden with a preset value
2. Create a form with the desired fields
3. Do not link a form field to the Jira Summary field
4. Within the form settings, select Create new issue and associate it with the Request Type from step one
5. Use the link provided on the settings page, selecting the project, request type and form
6. Complete the form and go to submit it

Expected Results

The form is submitted and the request type is created with the form data.

Actual Results

A generic error is seen indicating "We couldn't create your issue. Please try again later".

Within the browser DevTools network tab the following HTTP 400 error is seen:

Request URL: https://your-site.atlassian.net/gateway/api/proforma/cloudid/your-cloud-id/api/2/createissue
Request Method: PUT
Status code: 400

Workaround

At this time the workaround is either to link a form field to the Jira Summary field or to show the hidden Summary Field within the Request Type's Request form.