Using build-a-bundle with a pre-order?

So, I want to purchase a selection of packs for the Sims 4, and I want to use the build-a-bundle thing to do it (you know, the thing where you select an expansion pack, a game pack and a stuff pack and it gives you a tiny bit of a discount). The thing is, one of these is the High School expansion, and I was wondering if origin would allow me to do that - I've tried, and it just tells me I own all the expansion packs and thus cannot view the bundle builder page (though I do not own all the game packs and stuff packs, and I do not own high school. obviously.).
Is this a bug or a feature? Should I be able to do this?

Yes, I have asked EA technical support. They're not helping.