I have found the reason.
My first material was an empty material which turned on the frame of my windows.
I have deleted this first material and shift my wall reference about the same thickness.
Christophe - FRANCE
Archicad Designer and Teacher
Archicad 15 to 26 FRA FULL
OS 11.6 Big Sur - MacBook Pro 2015 - 16Go RAM"Quality is never an accident ; it's always the result of an intelligent effort" John Ruskin