For several months Disney Dining seems to have been incapable of loading their ADR openings in a timely manner. Frustrating as it is, it's not uncommon to find on your 180 day that one or more of the restaurants you want have not loaded into to the system. So you'll need to spend time ( that you could be spending elsewhere), checking again and again until it finally appears.
Gee, do I sound bitter?
Hopefully your dates will open up soon.
OTOH, Dec dates have been open for a while. They could possibly be booked, especially for the week around Christmas.