serial franchise and not

[vinci16]

hello to everyone, I have a problem with the visibility of the bending edges (not the line but just the edge).
in practice in certain files the edge you see and in others you don't see, I couldn't find the way to change this specific, can you help me?
thanks to all for the help, a greeting
ps: I put an image that makes clear the difference between a file and another

Andrea

 

[MassiVonWeizen]

right button on flat repetition and tick to join faces

 

[vinci16]

right button on flat repetition and tick to join faces

Thank you very much, very kind as always.
a greeting