Port 22 works from LAN IP address but port 2222 does not work from duckdns address.

If you are testing from inside your network back to your WAN, unless there is a Hairpin NAT allowed, it wont work

Cyril

As in personal mail same result from mobile phone using mobile data. 

I can get my websites up from within the LAN using duckdns address so ports 80 and 443 work as expected but not others as far as I can make out.