[Elecraft] KXFL3 Installation Questions

[AL7CR]

I just completed installation of a used KXFL3 into my recent model KX3
and discovered a few oddities.
My KXFL3 has 10 pins not 12 as in the original version and not 9 as in
the tuning noise mod.  Was this  an interim configuration?  Did the
noise mod only cut two pins initially?  It seems to work properly, now
anyway see below.  Should I now remove the tenth pin or does it matter?
I carefully followed the most recent calibration instructions using the
“sniffer” loop.  I was initially able to obtain a null only on FL1.  The
gain and phase adjustments did nothing at all using FL2 or FL3.  I
assumed that I might have a faulty filter or that the 10 interface pin
configuration was causing a problem.  After several attempts, each
carefully following the directions, I spun the tuning knob rapidly
several rotations while attempting to null FL3.  The system then worked
perfectly and I was able to get a deep null.
I then went to FL2, without repowering the rig or changing any settings
but those as described in the procedure and neither the gain or phase
had any effect just as before.  Also just as before several rapid
rotations of the VFO knob resulted in normal behaviour and the ability
to obtain a deep null.
I can now switch between filters and set each of them immediately just
as the procedure describes.  I am pleased that the calibration was a
success but remain quite curious as to the cause of this strange
behavior.  Does anyone have any ideas?