@c1wren That is odd. The only thing I can imagine is the port is somehow incorrect. First few questions:
1) Are you using the micro controller or the Raspberry Pi version?
1b) If your using Raspberry Pi, are you using Dan’s OSPi program?
2) What port are you telling the web app to use?
Note: If you are using the micro controller, don’t bother setting a port unless you are using a non-default port.
If you are using the OSPi program, the default is 8080 (use by appending, :8080 to your IP).
3) Both your options sound like they are on a remote network compared to the OpenSprinkler itself, are you using a public IP?
Note: If the IP begins with 192.168, 172.16, or 10 it is a private IP. Use wimi.com to find your WAN IP.