I have two 6873i’s connected to a 400. For weeks now, the date & time appeared on the phones home screen. Now, it does not. It only appears on the screensaver and if I pick up the handset. I plugged a 6940 into the controller. The login screen appeared and the date and time was on it.
The only thing that I recall changed was that I upgraded the controller from R5.0 to R6.0 about a week ago.