I have a fibre system and recently upgraded my phones to an Advanced Phone Z Quad system. These work great but exactly every 30 mins, at 15 mins past the hour and 45 mins past the hour, the screen indicates an incoming call for 1 second then it returns to normal. There is no ringing and the call has no number.
However, this registers as a missed call... so if I go to bed at midnight and wake up at 8am, my phones show there have been 16 missed calls!!!
Any ideas what these regular calls every 30 mins are and how to stop them from being registered at missed calls?
Thank you in advance for your help.
