This also happened to me.There is speculation on the Celebrity boards (or maybe it was other social media groups) that it has something to do with the process of starting to split the loyalty programs (from the middle of January).
Anyway, what worked for me to fix it was to delete my Captain’s Club number from my Celebrity account, save, and then add it back and save again. That somehow fixed my tier and points on BOTH Celebrity and Azamara.
With my husband’s account, I just needed to delete and re-add his Azamara Circle #. That immediately restored my tier level and points.
Jane