I was on a call for about 30 minutes or so. Suddenly the call disconnected and the Sangoma S500 display said “provisioning” “checking firmware” before it was fully rebooted.
It is using a power brick. I’m not close to it at the moment but I remember that I picked one that can supply at least about 1.5A to it. Unless, the power brick is defective.
I don’t think that the PBX server was rebooted because as soon as the Sangoma s500 rebooted, it quickly reconnected. The timing difference had the server rebooted would had been more about 10 minutes gap.