Running 8.3.1, I found I am not able to retrieve ActiveAcked alarms of Medium priority in the alarm status table. ActiveUnacked alarms are picked up, but will disappear as soon as a user acknowledges them. The behavior is the same in both the alarm status table and via the queryStatus method.
Edit: I tested the same via another gateway (8.1.48) connected as a GNC, using this provider as a remote tag provider. The alarms are appearing in that gateway correctly.
Example. The acked medium alarm is present in one query, but not the filtered query:
Alarm status for the tag above, according to the tag browser:

