Urmet 1704/955 works but …

After consulting an Italian forum for Urmet intercoms they came up with a process to make the Urmet 1704/10a 1794/955 work. Configure it as an Urmet 1130/16. 1+ wire A2 to AC and wire A1 to R1 (so just 2 wires). It works, sound two way works and I can open the door. But what doesn’t work is the notification on my iPhone. No sound or vibration. Just a banner on the Lock Screen. On the other hand, on my Apple Watch I get a proper notification. I also have on another poor petty but using the same Ring app a Ring interphone and I get proper notifications for that device. My settings are set properly. Anyone have an idea why I’m not getting sound and vibration notifications ?