Re: Some of my expansion packs CAS items are showing up red/white with "?" marks
Hi @Miira18! Some CC skins and facial features were affected by the patch, and although this isn't the issue I've seen reported for them (usually it's related to Aliens), I wouldn't rule it out. It's also possible that you've got a couple of items in your Mods folder conflicting with each other.
I know you said you tested "vanilla", but I'd like to do a 100% test on that - the level including a whole new Sims 4 folder.
Drag your WHOLE Sims 4 folder to your desktop, so that it's gone from inside Electronic Arts. Restart the game so it generates a new one. Now start a new save. Do you still see the issue? If that solves the issue, we can start on isolating where the content problem is.