[Elecraft] PX3-KX3 display question

[Daniel M. Kruss]

My KX3-PX3_KXPA100 system works perfectly, however I cannot understand the PX3 display.  On either USB or LSB there is a significant, narrow signal spike which tracks the KX3 frequency.  On either USB or LSB it is at the edge of the cursor where the carrier (suppressed) would be.  There is no tone as I tune across it and it does not interfere with operation.  The waterfall does show a narrow trail.  If I change the XFIL from FL1 to FL2 then the spike moves to the center of the new, narrower passband. On CW it is in the middle of the passband.

Is this spike normal or am I setting something incorrectly?  I can send photos, if needed.

Thanks,

Dan  K9GDQ