Cannot make ssh tunnel work

I was trying to tunnel with “ssh -w” from my sailfish sony but cannot make it work.
Both tun devices are up and running, and I disabled the iptables to eliminate it as a potential source.
Ping from the server to the sailfish client, I can see (with tcpdump installed with zypper) the ping request and the ping reply, but on the server side, the tcpdump on the interface doesn’t show the reply.
Is it a missing function in the implemented openssh or did i miss a part?
Thank you very much for any reply.
Best regards