The arrows are designed to take you from and then back to previous collection and folder locations you've selected. The don't take you from photo to photo - your arrows on the keyboard move from photo-to-photo.
Many Thanks, Allan
In a message dated 1/29/2015 11:14:07 A.M. Eastern Standard Time,
Arrows lower left side of develope mode not moving to next pix when
clicking on it
created by Rikk Flohr (https://forums.adobe.com/people/RikkFlohr) in
Photoshop Lightroom - View the full discussion