This message has been here for awhile, so I’m sorry for taking so long to respond. I’m sure you’ve figured this out by now!
If not – please forgive me for stating the obvious here – but did you make sure the ceiling button is toggled on?

Again, this is not meant to insult your intelligence or anything! This is just the only other thing I can think of. (And believe me, it’s very easy to overlook the obvious – ask anyone who was in Sims Chat the day I freaked out and thought the game had stopped reading my CC folder, turns out I had somehow unchecked the button when you load up the game that says “enable custom content”….).
I’m not sure if there’s a keyboard shortcut or something, but I find that the ceilings accidentally get toggled off for me from time to time. 🙂