"[Forget about mysteries, ghosts and hardware failures in your RPi.]"
... always a pleasure to meet people like u.
>> is there a problem with docker and network?
Docker is using NAT (.. and port forwarding) . Make sure its configured correctling in your yaml file.
Can u "ping" the host (pi3) ? You said that u can't ssh into the machine. Which one ? The host or the docker image ?
If there is ssh already active on your host u might have to choose a different port to forward and connect.
Cheers
Helium