One way audio with TCP endpoints (UDP endpoints work fine)

Greetings all. I have been working on this issue for sometime now without any success. ANY help or insight would be greatly appreciated.

I have a system where I run the usual UDP on 5060 for some phones and I run TCP on another port. This might sound odd but I have multiple systems I run like that and it works beautifully. Well except in this case.

So the plan here was to run a softphone on a cellphone or PC for remote occasional use. The softphone runs on TCP and I get one way audio. Softphone audio makes it to the server but the server never sends audio back. Which causes the call to drop after a short period of time. If take that same softphone and swap it all over to UDP it works just fine.

If I look at captures when using TCP SIP conversations it appears (assuming I am looking at this correctly) that rport just picks the wrong port. That being the server side picks the wrong port, the softphone does what it should port wise.

I am thinking if I rebuild that box it would all work fine like the others but I am trying to avoid that.

Thanks!