Photoshop doesn't show editings on canvas until I zoom

Hi everybody,

I just got this terrible issue since few days: I can't see any edit I do on the canvas until I zoom in or out on the canvas itself.

This happens also when hiding layers: the hidden layers remains visibile until I zoom.

This make photoshop really unusable.

I attach a gif showing an example:

(here the direct link to GIF: https://dl.dropboxusercontent.com/content_link/tpeyELWhuGAoqf6VvKrLsBXPt54lhpdfDfwUT5wSNgdaYC5MLhsrhhXAVqgjy5O9/file?dl=0&duc_id=ixlabb8EDQIpeNCr5DtlKzjG75FqGyS32eWiUa0tC9ejDCDFRn3OWmE3HBXhCY2Z&raw=1&size=2048x1536&size_mode=3 )in this GIF a just create some rectangles and, as you can see, they are not visible on the canvas until I zoom in or out!

I already tried to delete PS Preferences and it doesn't wok.

PS version is 19.1.0 on Mac OSX 10.13.3

Can anybody please help me? thanks!