This is a bit annoying since most people would just like to do celestial dungeons instead of heroic and then jump into challenge mode. Since the celestials are harder, I think it’d make sense for them to give the heroic achievement. Since this was the case in cata, I assume it’s bugged?
This was indeed unexpected, +1 for fix!
This should work now, it did for me atleast. Was able to do CM after celestials