Pulling the dumbbell straight up when doing a one-arm row is a mistake. Instead, pull in more of a sweeping "J" motion with the dumbbell starting slightly in front of the shoulder.
The one-arm dumbbell row, performed with one knee and one hand supported on a bench, is often misused and mistaken for an upper back exercise to train the shoulder retractors. What's important to remember is that the fibers of many scapular retractors (like the rhomboids) travel in more of a horizontal pattern. Using a neutral grip to pull a dumbbell from ground-level straight up to a horizontal body doesn't make these muscles work effectively.
To really hit the lats, pull the dumbbell using more of a "drag" pattern that starts slightly in front of the shoulder and finishes closer to the mid-torso.