As explained, many times already on the forum, EVERY time you see something "double", it's NEVER a problem of the scenery, and it's always casued by a problem of another scenery AFCAD.
I'm sorry, but there's no other way around: if you seem something doubled, you HAVE an AFCAD you haven't found. This could also be cause the flickering too, because the ground polygons of the conflicting one are flickering with the one from the Zurich scenery.