Hi, Thanks for your quick response. I have filed a bug report (FB17320486). I am using res_nquery to do NAPTR lookup for SIP server domain. The current code uses c++ and directly uses methods in libresolv.

Hi, The issue is not specific to a particular system/network/VPN client. It is reproducible on multiple network and VPN. Updated sysdiagnose logs collected after reproducing the issue at 10:08 AM 24th April UTC. Attached in https://feedbackassistant.apple.com/feedback/17320486 The query using DNSServiceQueryRecord works fine with and without VPN in the same network. Thanks, Prabhu