If you add only NMS license then you can see Threat reports displayed on the dashboard however as soon as MDM license is added then Threat report is not displayed on the dashboard.
NMS Active Threat Report on the dashboard without MDM license:
Dashboard reports when MDM license added:
Active Threat report goes missing from the dashboard.
SMS 5.5
The original design was that if a customer wants to use multiple features (mdm, mam & nms) then Enterprise suite license will be applied instead of just two license features. Since, this was the case so dashboard would only show the reports that were for the main applied license instead of all of the licenses applied.
Now a license check is done within the MDM and MAM dashboards to see if a NMS license has been applied so then it can show the threat graphs.
This fix will be released in 5.5.1 release.