This may be an old post but the issue is still unresolved, or has it?
I have been having this issue since upgraded my mac to high sierra and now Mojave.
Recently, I tested Express account on my home computer, MacOS (Mojave) on a Mac Pro, and surprisingly the item list is in alphabetical order, but on my iMac in the office, it is not, I also tested on my Macbook with High Sierra (since that's the last highest version it could go) and still the item list are not in alphabetical order. I am not sure where this is happening, and there is no settings that I could change to make this works.
Hopefully someone could shed some lights on this.