FWIW - on 2015(417) -

When I open the Lead Sheet Window, whatever measure that I had highlighted from the Chord Sheet window shows as highlighted with a red border.

Then as I press the down arrow key, a new measure one row down in the Chord Sheet window becomes the current measure, which causes the Lead Sheet window to highlight that same measure number with a red border.

As I continue to press the down arrow key, a new measure in the Chord Sheet becomes the current measure, with the corresponding measure in the Lead Sheet highlighting with a red border.

Once I'm at the "bottom" of the Lead Sheet (so to speak) another press of the down arrow key causes the next "page" of the lead sheet to come into view.

Hope this helps...

Chris