MAC Yosemite, LR 5.7 & 5.6, when I use trackpad gesture to pinch in or out (zoom in or zoom out) in the grid module, all of my photos change their aspect ratio (they become squeezed in or out) also the grid moves to the left of right and some of the photos are not visible, I have to scroll left or right - this never occured before LR 5.5 or earlier.
This doesn't work for me Victoria 😞 Futhermore LR seems to render some of photos in bad aspect ratio, despite having previews and smartpreviews already for those photos.
I already started a support request by Adobe. Till now no solutions. It is probably a bug with Lightroom cc and Yosemite with the MacBook Pro trackpad pinch function. Please report to Adobe that more people are having this issue.