iOS visual voicemail malfunction
I’m posting here hoping someone will be able to help me. I encounter a strange behavior with visual voicemail on my iPhone.
I’m using an iPhone 12 Pro Max on the latest iOS version (14.5.1) with two SIM cards:
An Orange France eSIM
A Bouygues Telecom physical SIM
Both carrier settings versions are on 46.0
When I get a voicemail on the physical SIM card everything is working as expected, but when I get one on the eSIM, as long as NextDNS is enabled I won’t receive the voicemail notification, which is pretty annoying.
I was able to reproduce the same malfunction on two different iPhones with the same configuration. Nothing seems to be blocked in the logs so I can’t understand what’s wrong, especially since everything else (like VoLTE, WiFi Calling etc.) is working great.
Thanks you in advance
One of it's thread responses mentions telephony domain whitelisting & opening/forwarding specific ports. However that thread is in the context of American wireless carriers so you might have to research & modify the concept for the specific UK/France wireless carrier(s) you're using
I actually discovered something interesting. I had installed the NextDNS DNS profile on iOS. As soon as I removed it, my messages appeared on the voicemail. Even if I am behind a router configured to use NextDNS. So I suspect NextDNS is not blocking anything it should not. The issue seems to come from iOS and the way it uses DNS configuration. Could someone confirm ?
Could you try with the same profile you are currently using but excluding the domain "dav.orange.fr" (you can exclude specific domains on https://apple.nextdns.io, under Advanced), and tell us if that solves the issue?