I guess your lightmass settings are good because I see nice shadows in the upper corner… although it’s a different mesh! 
I don’t know how big your floor is and how much shadow information it has to hold…
Could you take a screenshot with the NOW settings and lighting only?
Also… how thick is that door? …looks really thin… do you have two sided material on it just in case? /and also set as double sided geometry/ …or to make it a lot thicker for a test bake and see if the shadowing is still bad… just ideas what I would try!