According to this documentation: https://wiki.openjdk.java.net/display/OpenJFX/ListView+User+Experience+Documentation ListView in single selection mode should ignore Shift key when Shift+UP is pressed.
Instead, if an item in the middle of the list is selected and Shift+UP is pressed, then selected value changes first from old value to null, and then from null to new value. When only UP is pressed, then correctly only one event occurs. This also allows to clear selection from the list even if this is disabled if Shift+UP is pressed when first item in ListView is selected.