Log Forwarder 1.2.0 Ipv6 not working

hi

I try to get the logforwarder v1.2.0 running on ipv6 only systems. I can configure the server but no messages is leaving the client even not if I use fqdn or hostname as target.

If I switch to an ipv4 target it runs without any problem. Someone any solution to get ipv6 working?