Custom field of Datepicker field type doesn't work on new issue view for Sub-task Issuetype

Issue Summary

Using the Datepicker field type on the new issue view for sub-task issuetype doesn't work. in order to determine this, make the field required on the sub-task issuetype and notice that the calendar doesn't pop out.

Environment

Jira Cloud

Steps to Reproduce

1. Create a custom field using the datepicker field type
2. Add this custom field to the Screen of a Project.
3. Make this field required in the field configuration.
4. Create a Parent Issue, then subsequently try to create a subtask inline in order to bring out the Create Screen to fill in a value for that custom field.

Expected Results

The calendar dialog should pop out for the user to select the required date and time for the custom field.

Actual Results

Notice, that the Calendar doesn't pop out and doesn't work. The calendar icon seems disabled

The below exception is thrown in the console log on Chrome:

Uncaught TypeError: Cannot read property 'DEF_DATE_FORMAT' of undefined
    at new Calendar (batch.js?adg3Enabled=true&devsummary=true&globalSidebarEnabled=true&jag=true&locale=en-US:4942)
    at n (batch.js?adg3Enabled=true&devsummary=true&globalSidebarEnabled=true&jag=true&locale=en-US:4945)
    at HTMLAnchorElement.<anonymous> (batch.js?adg3Enabled=true&devsummary=true&globalSidebarEnabled=true&jag=true&locale=en-US:4945)
    at HTMLAnchorElement.dispatch (batch.js?adg3Enabled=true&devsummary=true&globalSidebarEnabled=true&jag=true&locale=en-US:82)
    at HTMLAnchorElement.h (batch.js?adg3Enabled=true&devsummary=true&globalSidebarEnabled=true&jag=true&locale=en-US:74)

Notes

On Firefox shows references to TypeError: Calendar._TT is undefined Learn more

Workaround

• Change to the Old Issue view https://<your-instance>.atlassian.net/browse/ABC-123?oldIssueView=true and perform the same action and it works
• Manually enter the date and time value on the field as it allows editing.