In sshd, you should have GatewayPorts yes .
If you whitelist the port 11434 as per https://docs.cloudron.io/networking/#whitelist-ports , it should work . I tested this and it works with your commands.
But, I don't completely understand it. I found that 11434 also gets open to the world In your example, curl localhost:11434 works.. why? aren't we just binding to 172.18.0.1 ?