My status: I have a JIRA next-gen board with plenty of issues.
My problem: Issues in the last column, labelled "Complete" are not automatically removed after 14 days per the documentation. For example, here is an issue that was last updated on November 26, 2019, that is still in my "Complete" column.
Why this is important? Completed and now non-relevant issues make it difficult for me to easily triage my board and see the state of the current project.
Example: 
