Rattle in mechanism?

[dormermike]

Just had new uPVC rehau windows installed and when the window (any window) is open, if you bang on the frame gently the metal locking mechanism rattles. Installer said it was normal.

Is that expected? My old windows didn't rattle like that, makes them feel cheap tbh. It doesn't seem to cause issues in wind etc so maybe I am being too picky.

Thanks

 

[crank39]

Just checked a few of mine and they rattle too