On a brand-new snom D375 phone configured for our PBX, the phone frequently switches to DND mode. This is not displayed on the screen but when anyone calls the phone does not ring, and the caller gets the PBX announcement that the phone cannot be reached - just like it would if we switch DND on manually.
Restarting the phone solves this, but only for about 1 or 2 hours, then it is again off and cannot be reached.
The phone runs software 8.9.x.x, latest release, nothing has been updated on it, just out of the box, plugged in and provisioned by the PBX.
This does not happen with any other phone in the system. Plugging in an old snom 320 (software version 220.127.116.11) instead on the same number does not give that problem.
What does this mean? Is the phone broken, dead on arrival? I cannot find any forum entry for that problem, Google turns up nothing.
We already answered you via ticketing system. We will follow up there if you do not mind