[SR-Users] IPV6 header in IPV4 : ACK for 200 OK never received

Hello, I encounter unexpected behavior. The call flow is: UAC --> Kamailio + Rtpengine (full ipv4) --> Asterisk (full IPV4). I configured the uac to use IPV4 but the SIP INVITES include IPV6 in headers and sdp messages. I think this is a bug on the UAC side. Example: 1. UAC INVITE *INVITE* sip:xxx@sip.xxx.com SIP/2.0 Via: SIP/2.0/TLS [2a04:cec0:101a:ebe2:9949:d81c:23a6:ae10]:42580;branch=*z9hG4bK.I8U1RQDbW* ;rport ..... ..... v=0 o=59130c8f7268a_2 2922 1557 IN IP6 2a04:cec0:101a:ebe2:9949:d81c:23a6:ae10 s=Talk c=IN IP6 2a04:cec0:101a:ebe2:9949:d81c:23a6:ae10 2. We sent 200 OK response like : Via: SIP/2.0/TLS [2a04:cec0:101a:ebe2:9949:d81c:23a6:ae10]:42580;received=80.214.78.1;branch= *z9hG4bK.I8U1RQDbW*;rport=1364 v=0 o=x 887503534 887503534 IN IP4 51.159.2.164 s=x c=IN IP4 51.159.2.164 3. We never receive the ACK message. Is there a Kamailio or Rtpengine solution to solve the problem? Any help will be very appreciate. Abdoul OSSENI https://www.africallshop.com/