I'm having exactly the same problem. I've set up my Open-VPN docker exactly as described in the very useful tutorial (though I have a static ip so I skipped the dynamic DNS bit) have my port forwarding setup on my router exactly as I have setup with currently working applications like Plex (which I can access from outside of my LAN). Using an online port checking tool (like this one) shows that 1194 is not open, when other ports I've setup in exactly the same way do show up as open. I've turned off the router firewall and that made no difference.
I've tried to connect to Open-VPN on my phone over 4G and using friends and public wifi and it just tries to connect and eventually times out.
Any thoughts on troubleshooting would be greatly appreciated.
Happy 2018 all!
Thanks,
Peter