Theres another service LocalExpose I asked about, and they said this.
"Hey, thanks for contacting us about this.
Your issue is very likely Carrier-Grade NAT (CG-NAT) which basically means that T-Mobile's public IP will not ever forward directly to your actual IP address, because T-Mobile does not give your gateway a unique public address. We have a lot of customers on T-Mobile, but that does not necessarily mean that LocalXpose is compatible with GameRanger.
Whether we can solve your issue will depend on whether you can configure your public address in GameRanger. It sounds like GameRanger assumes your T-Mobile IP is the address it should be using, and if that is the case -- unfortunately that is not something that LocalXpose can change.
However, if GameRanger allows you to configure your own address and port, it would be easy to use LocalXpose to forward that address to your actual machine. Unfortunately, I suspect based on limited web searching (and very limited docs on the GameRanger website) that GameRanger is somewhat limited in its configuration.
Another problem here is that we do not support TCP and UDP on the same port, and it seems (based on limited web searching) that GameRanger also expects 16000 to listen for both TCP and UDP traffic. But that may not be a hard requirement, I don't know.
So, as of right now I don't believer GameRanger will allow you to define your public IP and ports independently, so you most likely wouldn't want to waste time trying to set up LocalXpose. And I'm very sorry about that!"