Shangri-La - Mars or Earth?

I need to know, lore experts please step forward. Does Shangri-La take place on mars, and do we have any concrete evidence to support this claim. I heard the theories about teleporting to the Mars version of Shangri-La during the eclipse mode, and returning to the Earth version when eclipse ends.

I have explored the side ee on Tag Der Toten in BO4, where you view Mars from what is supposed to me Phobos one of the moons of Mars, with the Shangri-La theme music playing in the background. This is the only evidence I know about so far, and even that doesn't 100% confirm it.

Are there any other theories or specific evidence to where Shangri-La actually takes place?