Mobian 'HotSpot"

[biketool]

Turns out it was a carrier issue on both  carriers.

I spent a long time talking to an AT&T rep.  he "reset"  something on my account and now  "data and hot spot work on my daily driver".

Later I talked to a rep. at Pure Talk and it turned out you just need to ask them to turn on your hot spot capability,  it is off by default.
  >  My "test" phones are on Pure Talk  <

Wait...
How can a mobile service operator have any effect on hotspot?
This is an app internal to the phone doing some IP tables stuff to route data through what could be thought of as like a VPN or IP tunnel, you could think of the NAT as using data in the exact same way as a web browser or any other app then redirecting it once it has split it out to the NAT clients. 
I was under the impression that operator controlled hotspot was only possible with phones that had a custom OS controlled by the mobile service provider so they could have a lock on and charge extra for hotspot data.
Anything else would be some voodoo magic in an otherwise rational FOSS world with IP tables routing.
The only thing I can think of is if they are doing packet inspection and see/filter out NAT in the packets, a VPN or a SSH tunnel should fix that then.