CC showing up in CAS but not in game

@BipSqueeek  When you save the game with your custom content missing (whether the files are missing or are present but not being loaded), it's removed and replaced, or sometimes not replaced, and re-adding the cc won't put it back on your sims.  It's as if you reassigned their clothing yourself.

If you don't want to have to reapply all the cc manually, the only thing you can do is load a backup save where you never saved the progress with the cc missing.  If you still have one where your sims have all their cc, it's simple enough to recover it and continue playing from there.

https://sims4.crinrict.com/eng/2014/09/save-games/#wiederherstellen