I got another model, this one is a NURBS, and guess what, all worked perfectly. I can now use SW functions to process the entire model.
BTW, the first model was POLYGONAL.
I am not sure if the difference was between NURBS and POLYGONAL or just the way POLYGONAL model was made, but it at least worked.
Thank you, all for help. I appreciate that.
Not I will start to scale the model so it will fit 70mm EDF's and to install electronics and FPV gear.