I think the contradiction is surface level.

Something can be a store of wealth and not be money. Eg. real estate.

Money is by definition a medium of exchange, its "primary function."But not everything can be money. Value is a prerequisite, just like divisibility, fungibility, etc. 

 Yes, and the argument is that Bitcoin more resembles digital real estate

Menger/Mises are saying the exact opposite of your last point. According to them store of value *is not* a prerequisite for money. But if you think they are wrong that is okay. 

 I think you're missing the context of that quote. Anyways, I think what I think.