Phoscon not remembering time zone changes between reboots

I’m running a different time zone in the OS than set in the Phoscon web UI. When setting the time zone in the UI, all schedules work fine regardless of the OS tz; however, at every reboot, the Phoscon time zone is reset to the OS one, so this is not saved anywhere. Is this a bug, or do I have to modify a settings file somewhere?