When cycling through Parallel Books with the right arrow key, the ESV Study Bible occasionally just shifts left instead of advancing to the next book. It has happened repeatedly but not consistently.
the ESV Study Bible occasionally just shifts left instead of advancing to the next book
Bible "shifts left" is not clear.
But right-arrow from that book at Gen12:1 can end up at page xii and now fixates on Ruth 1:1 of "Old Testament Use of the Old Testament: Book-by-Book" when it should go to Gen 9.
This is caused by the very wide table just a bit above your current location in the ESV Study Bible (note the wide scrollbar at the bottom of the view in your screenshot). If you continue to press the right arrow key, it will continue to scroll over until it hits the edge, and then it should shift to the next parallel book as expected.