I'm using a bunch of non-3cx clients with the PBX and one of them is a native Android SIP client. Lately, the incoming calls from local PBX users show extension@IP rather than email@example.com in the native Android SIP client. Now, I don't know when this started happening, I was a happy customer running v15 on a VM in Google Cloud until attempt to upgrade to Debian 9 borked the VM (I know, should have made a snapshot) and some time later I killed the old, non-working VM and started fresh with the new cloud install and restore from backup. I'm on version 15.5.0 and the Standard Perpetual license. I have configured the local SIP domain and the DNS records according to https://www.3cx.com/blog/voip-howto/direct-sip/ and I have no problem calling (and reaching) firstname.lastname@example.org nor email@example.com and I can use either 3cx FQDN or my own domain when registering soft phones -- still on incoming calls I get the extension@IP rather than extension@FQDN. Any idea how to fix that?