I can't find if this has been addressed, but I am a Campaign Organizer/DM, with a subscription, Legendary Bundle, and content sharing enabled.

I have disabled options that I don't want to allow in my game, including Acquisitions Incorporated. But the backgrounds from that book are still showing up in my players character creator options.

What is the issue going on here?

Could the players own the books themselves? That would mean the content would still display, you can't stop people from accessing content they own themselves

Ok. So I've seen mods answer this enough to have learned something.

The "manage content" settings prevents players from reading the compendium (good for preventing spoilers), but doesn't prevent access to things on character sheets (so items in campaigns can be gained).

So then can we get switches on the Character sheets for Acq Inc like we got for Eberron, Ravnica, and Homebrew?

Acq Inc is Forgotten Realms set content and is thus considered 'core' D&D. Only stuff that isn't core D&D, ie another setting, gets a toggle. This is why Eberron, Rick & Morty, Critical Role, Homebrew and Magic the Gathering content gets toggles.

More granular character builder content control is on the roadmap

Honestly, I'd like to be able to toggle any and all books individually in preferences (maybe a pop-up window for it). That would also be useful for AL players.

From what I gather that's what they plan to do to improve AL compatibility - no idea when it's likely to happen though.