Regarding clock synchronization on Room panels:
We are using the Android built-in clock synchronization, this uses NTP on UDP123 for synchronization. However the target NTP server is not known as android tries to be clever and assigns different NTP servers based on geolocation and ToD.
To get this working you need to allow for NTP (UDP 123) traffic from the inside ->internet for ALL destinations.
There is now a new panel software available that supports manual setting of the NTP server.
The setting needs to be changed on each panel, and can not be managed centrally.