Siren stops beeping on exit

Since the latest firmware update, my external Siren stops beeping after I open the exit door. I can hear it beeping when I set the alarm to "Away', but as soon as I open the exit door, it stops. I've contacted tech support who instructed me to conduct a test, cycle the power on the Siren, remove the Siren from the system then add it back, and cycle the power on the Base Station, all of which I did with no success. Anybody else having this problem? Hoping that a future firmware update fixes it.