Hardware Test Platform & Setup:

FCB1010 (no UNO chip)

Active switch transmitting none of the 5  program changes, or MIDI note.

Same switch sending any single CC number on MIDI Channel 2.
[not the two CCs available per-switch, and not using the Controller Toggle function – (FCB1010 manual – Section 2.5)]

FCB1010 MIDI OUT to MIDI IN of PitchFactor 3.0.0beta[16]

System settings-> MIDI:

RCV CH: 2

RCV CTL: FS3 > matching CC number on FCB1010
[no other conflicting RCV CTL assignments]

OUTPUT: THRU

CLK IN: OFF

CLK OUT: Tested at both ON & OFF settings

Test Results:

Sent CC value 0-63:
Bank mode: FCB1010 switch does nothing (Tap Tempo unaffected by incoming CC)
Play mode: FCB1010 switch increments Bank number

Sent CC value 64-127:
Bank mode: FCB1010 switch determines Tap Tempo
Play mode: FCB1010 switch determines Tap Tempo

Note: Presets tested alternately at TMP ON and TMP OFF settings with functionally identical results

I have the same results using BK+, BK-, FS1, and FS2 in Bank / Play modes as detailed in the OP.  At one point, I did have difficulty getting FS3 to LEARN via MIDI (RCV CTL + two right button presses), but I can't reproduce those conditions in a "recipe".