Snapping Notify to Frames in Animation Sequence not working

When I enable Snapping to Frames in an Animation Sequence (right-click the ruler/timeline), my notifies don’t snap to the frame markers.

Unreal documents the expected behavior perfectly in this GIF here, and I can’t get mine to behave that way.

managing2

Can anybody get this feature to work? I’m on 5.4, thank you.