This provides an answer to the Unknown compatibility for CMJ when users run the Jira update check.
User is seeing the following Unknown compatibility section for CMJ when running the Jira update check on their Jira instance.
Configuration Manager Core Bundle
Configuration Manager for Jira SPI Bundle
The CMJ Core and SPI bundle apps are part of the whole Configuration Manager for Jira app family and installed together with the app.
Therefore, those bundle apps have shared functionality and are part of the CMJ package and cannot be installed separately from the marketplace as the UPM cannot know their compatibility due to them not being listed on the marketplace officially.
This explains why we are seeing incompatibility in the UPM but that is not something to be concerned. To sum it up: CMJ and the supporting apps CMJ Core and SPI bundle are fully compatible with Jira 8.XX.X.