Server Address When on Wifi vs. LTE/Internet

[MikeG.6.5]

Yeah, that's pretty much what Kaptian Hack said with his reply above. If you can't replace the box with one that does support the outside IP, you are pretty well screwed with their hardware for this... Sad as it is to say....

That's one of the problems with ISP's when they use proprietary hardware and lock out some functions.... This is intentional, BTW.... They don't want you running a server on their networks, which is basically what you are trying to do...