Saving Date to Display changes in the Jira Issues Calendar Widget fails

Issue Summary

In v6.0.1 of the Jira Calendar Plugin, the Date to Display dropdown on the Jira Issues Calendar gadget no longer saves the selected value successfully. Saving an alternative option such as 'Due Date' and viewing the calendar shows 'Created' as the selected option.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Configure a new Jira instance on v9.5.1 and create a project with sample data
2. Install the Jira Issues Calendar plugin v6.0.1
3. Visit Manage Dashboards, create a new dashboard, and add the Jira Issues Calendar gadget
4. On the initial configuration or by using the 3 dot menu's 'Edit' option, select the test project and change the value of 'Date to Display' from 'Created' to any other value
5. Save changes to the gadget

Expected Results

• If the value was changed to 'Due Date' or any other option and saved it should reflect on the Calendar

Actual Results

• The change reverts after saving and 'Created' displays on the calendar, severely limiting visibility options in the gadget

Workaround

• The only currently known workaround is to downgrade the plugin version to v6.0.0 by uninstalling v6.0.1 and installing v6.0.0 from the Atlassian Marketplace manually