Your settings seem correct, and Source Port should certainly not be empty when
doing port-forwarding (or there is nothing to forward).
So it seems that port 22 is being blocked. It works when you self-loop from your
computer to your computer through the router, but does not work from the
To find out why it is blocked, check first the router if this port is not allowed.
for your router is basically empty, so you will have to find it out the hard way
from the router's login page.
Ports are often called "services" and this is normally found in the Firewall
section of the settings.
Once you are sure that the port should not be blocked on your side, this leaves
Try a service such as
GRC | ShieldsUP!,
option Common Ports, to see which ports are open, and check port 22.
If port 22 is blocked, this means that either your router is still blocking it,
or that the ISP does.
If any other port is open, you might use it as the Source port instead of port 22.
If none of the above worked, contacting your ISP Support might help.
Note: The router might have a DMZ setting to direct everything to your computer.
Avoid it, as it is too dangerous.