Bitbucket does not retrieve the default values for Jira fields

Issue Summary

When creating a Jira issue from Bitbucket Pull Request, Bitbucket does not retain the default field values for standard or custom fields.

Steps to Reproduce

1. Set a custom default field value for Priority field. I set to 'High' as 'Highest is the default'
2. Create a custom field in Jira and define a default value
3. Create a Jira issue from Jira to confirm the default values
4. From the Bitbucket Pull Request, create a Jira issue

Expected Results

In the modal window, the Priority field should default to your custom value and your custom field should show your default value.

Actual Results

The Priority displayed is the first in the list.

My custom field shows "none".

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available

Update 13/11/2019 AEDT:

This bug can also manifest in custom fields not displaying their original values when transitioning tickets from within the Bitbucket.
I.e. instead of the original values assigned to the fields in the JRIA ticket, BItbucket modal window will show them as blank.

The bug fix seems to address this issue as well.