Issue: Rapidly scrolling up or down often creates an unintended blank space (margin) at the top or bottom of the tab list. Symptom: When this gap appears, the mouse cursor's focus becomes misaligned with the actual tab selection point by the height of that gap. Behavior: Scrolling back toward the gap usually forces it to disappear, which also restores the correct alignment between the cursor and the selection point. Reproducibility: The exact trigger is inconsistent. While it happens most often during fast scrolling, it sometimes occurs during slow scrolls as well. The frequency is unpredictable—sometimes occurring every time, and other times once in five attempts.