Your edit fixes some of the problems.
But main problem here: part of the building is not mapped. (Multistorey ramp or "stairwell" but for cars, don't know how it's properly called).
It can be seen on aerial.

Also, regarding parking building part - don't know how correct it is. I mean at least this east part of building is shared between parking and offices. Maybe it would be good idea to remove parking part and isles, and leave just parking entrance/exits on building edges?
Like it is done here: https://www.openstreetmap.org/node/10745369561