Ah, I had a feeling it was you. Aldi is this Germany grocery discounter (founded by the same guys that own Trader Joes, but then I don’t know whether they are in Canada, either, ey?) that has since expanded to the East Coast and many European countries.
First I was thinking cocoa butter content, but then I thought about the chemistry a bit more, and I think it’s actually the emulsifier in the chocolate, because that’s really what would help with the curdling. The ingredient list for the white chocolate from Aldi lists: White Chocolate (Sugar, Cocoa butter, whole milk powder, cream powder, lactose, soy lecithin emulsifier, salt, flavor vanillin), whey powder, buttermilk powder. The Guittard doesn’t list ingredients.