NAT settings, i know But read... :)

Ok through the years ive used tons of glinet modems, and know cgnat is usually a problem with getting open nat on cellular modems.

However i have one XE300 with ac35af quectel modem which gives my buddy open NAT on ps5 (or at least a usable nat 2) while all the other modems ive taken to his house to upgrade him always get worse type 3 and he cant party up or join chats.

He always says he doesn't need an upgrade and we leave it at that, however i would like some expert help on figuring out what's up with this particular unit that makes it work.

is it the connection profile, a particular firmware, is it the local band setup, apns, is it local port settings, lack of aggregation?.. i basically would like to dump all relevant settings and try to replicate on other units i have to further learn and possibly help myself and others. this should be replicable.. its not sorcery

Someone knowledgeable please give me a full list of what settings to check with what commands and lets get to the bottom of this.

on tmo tablet line if that matters. (no static ip) or other add ons.

Whether if the NAT2 or 3 in the router, depends on your mobile operator of the cellular network, or the connect environment of the wired ISP.

If in the NAT 3, enable the special port in the port forwarding of the router, thus also works the same as the NAT2.