NGS CBT: SG Shop Not Working

So they want us to test out the player shops by buying and selling things which seems to be working fine because I purchased a Premium Set with the AC they gave us, but then they want us to test Material Storage as well. So, I go to buy a Material Storage Pass and the SG Shop is greyed out making it unselectable. Does anyone know the reason for this? Thanks.

To buy Material Storage, you have to select Material Storage from the Storage interface and it will give you the option to buy it. I'm not sure why it isn't just in the SG Shop, but at least it is still possible to buy.

how? it just says "not purchased"

@Eritogema Click on it like you are trying to access it.