RAM SS - Frame Analysis - Sloped Steel and Decking

I originally modeled my building with flat steel since I was not sure how we would slope the steel for roof drainage.  We have determined the slope so I went back into the modeler and adjusted top of columns and story heights to match my building.  When I reran my building, the forces were drastically different and when I look at the displacements too my roof decking is displacing freely vertically.  It seems like the roof decking is no longer acting as a unit  with major displacement in the center of the bays.  What did I do wrong?  I removed the decking prior to sloping the steel and then reapplied so my 3D model looks correct.

Thanks,

Chris