Unable to access Flex 6300 (V2.6.2) remotely after network changes

Tim (and Community),

we still have an ongoing issue with respect to gaining access to our Flex remotely. We need to know how to troubleshoot this deeper than what is available. We have attempted every known solution and reconfigured and reloaded everything at least twice. we are sure this is a network configuration issue, but cannot find the "secret" path that is being blocked that will not let a remote Smartlink session connect and use the radio.

1. We have a green light self test. (see attached picture)
2. Port forwarding is configured as required (also attached)
3. Tracert to 8.8.8.8 only shows one private IP address (also attached)
4. Radio shows as if it is available remotely to access, but always fails to connect (from several computers and an IOS device)
5. More misc info attached
6. Smart SDR has been removed on several computers and reinstalled. The radio has been re-enabled on the Smartlink system at least twice.
7. No troubleshooting efforts appear to indicate why the radio appears to be available remotely (and the remote computer using SmartSDR remotely can also disconnect a local LAN connection that may be using it) but can never connect to it.