Greek MashUp not working offline?

Bought Greek Myth mash up and works great.
But as soon as i am not connected to wifi (while not home or whatever) i can't play/create any mash up world. (greek/redstone)
Can click the "Play" button after typing in name, survival etc. in world creation but nothing happens.
Offlinerights are enabled in microsoft store options.

Microsoft Surface Pro 4