Ah, okay, so it's not about what kind of spell slot we can use to cast spells, but to create sorcery points. I get it now!

I'm guessing that this is something that has been reported to Larian via the "Report a Bug" link up the top of the launcher? That would be the best way to get info from them about whether they see this as a bug to be fixed, or whether it's per their design.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"