Please double check if the inbound TCP 5246 is properly forwarded. If you “nc” or “telnet” to port 5246 on the ICA’s public IP from external, you should see a greeting message like “SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.4”.
If you’re sure the device’s outgoing port 5246 to the ICA is not blocked, please enable Remote Assistance on the ICA’s control panel page and DM me its s/n. Let me check for you remotely.