Dynamo hangs / crashes when creating FamilyInstance.FromPointAndLevel

I’m using a series of mullions as Elements then converting to Solids to find their Centroid, and placing a FamilyInstance.FromPointAndLevel node.

The moment I connect the Level parameter (after connecting the point and familyType), Dynamo and Revit hang (crash).
(note - I uninstalled all Dynamo extensions before trying this.)

When trying the same with FamilyInstance.ByPoint, it works fine.
But, in the case of ByPoint, the Family that was creates as a 100mm Conceptual Mass on the Origin (0,0,0), appears to be starting 50mm “too high”.

So basically 2 questions to sum up:

  1. Why is FamilyInstance.FromPointAndLevel freezing the program?
  2. Why is an Origin created Mass, being Instanced from Dynamo at a position 50% off-point