Upgrade Jira: App compatibility limiting me to version

[Mark Hitt]

I'd like to upgrade my Jira software server version to 8.20.9 as suggested under 'plan your upgrade' in Jira, but when I run 'app compatibility', Jira Advanced roadmaps is limiting me to version 8.14.1.  I've upgraded a test server to 8.20.9 with Jira Advanced Roadmaps enabled and running.

  Why is that I can run version 8.20.9 successfully with Advanced Roadmaps on a test server, have the server suggest the current LTS version 8.20.9 but the app compatibility tool is telling me to install 8.14.1?

Which version should I install?