I have a part that I imported from an iges file.  I did an check after import, no bad geometry or surfaces.

Saved it as a SolidWorks part.

I want to make create a sketch on a planer surface and but Solidworks won't let me.  It's a true plane, no curvature, I used the curvature tool.

However if I pick a planer surface and use the reference command plane, it will create a plane tangent to, not parallel to the surface I've picked.

How do I get around this?