A common reason the remote will not function after it was working is that someone accidentally pressed one of the "camera select" buttons at the top of your remote. Press "camera select 1" and see if you gain control of your camera again. If that doesn't work please try "camera select 2 and then 3". This feature exists in the camera so you can have up to 3 Huddlecams in a room able to be controlled by one remote.
If this does not fix your issue try replacing your remote controller batteries. If this still does not fix your issue then there is most likely IR interference in your room. Try holding the remote control right up to the front of your Huddlecam to see if you can get it to accept a remote control command. You may need to turn off lights and other electrical devices that can cause IR interference. If you do find interference to be a cause for the remote controller not working, using serial control is a possibility to address the issue. This would involve hooking up the camera to a Joystick or a PC to allow for PTZ camera control.