Hi there,
Check if you can export the report from the RD Licensing manager for the total users. You can create a report, save it to a .csv file, and then view the CSV file in Notepad/Excel. You can do this in RD Licensing Manager by right-clicking on the server name, choosing to Create Report -- Per User CAL Usage, and then after you have the report right-click on it and choose to save it as CSV.
If you get the correct number of users in the report then you must have configured the manager in the wrong way.
Here is a thread as well that discusses the same issue and you can try out some troubleshooting steps from this and see if that helps you to sort the Issue.
Why RD license Manager console issued showing "0" & can we check how many Cals license used from a server
https://social.technet.microsoft.com/Forums/ie/en-US/4023be76-4477-490f-a8c4-c4543349ad00/why-rd-license-manager-console-issued-showing-quot0quot-amp-can-we-check-how-many-cals?forum=winserverTS
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