Solved Prosody s2s connection-timeout in jail

I installed prosody in a jail redirect the traffic to it with pf. With this config:

rdr on $EXT proto { tcp, udp } from any to any port $XMPP_PORTS ->

And for unknown reasons at least for me the s2s part just fails with error messages like this

Sep 27 20:39:21 s2sin804074c40 info incoming s2s stream otherdomain.tdl->domain.tdl closed: connection-timeout
Sep 27 20:39:21 adns error Error sending DNS query: Protocol not supported

And I'm out of ideas why or what on my server is failing.

Connecting on 5269 with telnet works and return some xml, the c2s component works flawless.

So what is the problem why can't prosody not connect to other xmpp server?

The full config and more of my log
Looking at the second message I'm guessing the jail is unable to resolve. So you might want to check its DNS settings.
I had ipv6 nameservers in my /etc/resolv.conf file. I removed them and everything worked as expected.