Why is my CAS stuck like this ever since the update?

maxxylynn Looks like you still have broken mods. See Broken/Updated Mods & CC. Note that not all mods are reported here (for reasons given at the start of that post). Info on how to narrow down a broken mod is in How to Use Mods and CC

My game did this too and I fixed it by deleting the "More Columns in CAS" mod by Weerbesu and redownloading it because that creator released a new version after the most recent pack update. Not sure if you have that mod, it might be a different mod for you but that's just what worked for me! Maybe move each of your mods out one by one into a different folder and start the game until you find which one is broken.