Mobile Devices have disappeared from MDM

Mobile Devices have disappeared from MDM

I migrated from solely using MDM to what is now Endpoint Central and initially all of the items in MDM moved over, and where visible in Endpoint central under the MDM tab. Recently the remaining phones have disappeared from the MDM tab, but the devices themselves are still showing as connected and event are still showing in the Audit Log feed.

Has anyone seen this before and any clues on fixing this, without re-enrolling the devices.

                  New to ADSelfService Plus?