Cueing issue

There is not much downward force on the cueing device, to make it reach the full extent of its travel toward the surface of the LP (=VTF plus some mechanical advantage due to the location of the cueing device near to the pivot).  In this case, the cueing device may just be sticking at some point before it hits the bottom of its travel, on the occasions where you notice.  You might look into ways to lubricate it or maybe replace the damping fluid with something less viscous.  The Alphason is decades old, so maybe new damping fluid is in order.