Flair calling for Heat while vent is closed!

Hi, Perhaps I can get an explanation. This has happened at random times throughout the year both in winter and summer. Happened tonight and remembered to post here in forum. I have my entire first floor with flair vents, 9 in total. We use the fireplace most nights, and set all rooms, but one, to “inactive”. It’s a room that my son hangs out in. The room does not get any overflow from fireplace and so it stays active to keep it warm. I can hear our forced air heat on, warming that room and know that flair has called for heat. The room is set for 69. The room reaches that 69, heat is still on, but the VENT IS CLOSED! It just keeps running until I set that room to inactive. No other rooms are active just one. This happens in summer (with ac), winter, etc,,,,, every so often. I only catch it when I realize the system has been running forever. And because of back pressure precautions, the inactive rooms get warmer (or cooler in summer) while the vent is closed in the only room that is active. Very frustrating! Flair is the Set Point controller and I have an ecobee as a thermostat with sensors in every room. I have 3 pucks on the floor with 9 Flair vents.