FCB1010 programming issue


Dear all, 

My setup:

- Brand new FCB1010 MIDI controller, firmware 2.50.1 E

- Roland UM-ONE Mk2 MIDI-to-USB interface

- Windows 10 PC

- 3rd party software: MIDI-OX, FCB1010 Manager

I started to manually program MIDI messages (notes) sent by the footswitches in order to control Ableton. The programming went well for footswitches 1 to 4 (test with MIDI-OX: OK, MIDI mapping in Ableton: OK). But when I programmed the footswitch 5, I noticed that the note programmed on footswitch 5 also got programmed on the footswitch 1 (it replaced the MIDI message that I initially set on footswitch 1). The same thing happened for the footwsitch 6 - its note also got programmed on the footswitch 2, etc. Then I factory reset my FCB1010 and read back all the presets with FCB Manager software. A strange pattern emerged (see attachment): the footswitches on my FCB1010 seem to be "routed" in pairs with offset 4 (5 is routed on 1, 6 is routed on 2, ...). I tried everything and it seems impossible to me to program these footswitches with different MIDI messages...   

I would not blame the MIDI-to-USB interface for this: I get the same issue when I do the manual programming ("tapdance"), when the FCB1010 is not even connected to the PC. Even then I can tell what the result will be: manual note programming, footswitch 10 LED blinking, before I enter the new value the FCB1010 shows the old one (for ex. I program footswitch 1 with note 60 - OK, then I program footswitch 5 with note 64 - OK, then I want to program footswitch 1 again and the display "suggests the previous note" 64, which I never programmed on footswitch 1!).

I also get the issue when I program MIDI messages via SysEx using FCB1010 Manager. 

This happens with MIDI messages of different types: PC, CC, notes...

Am I doing something wrong? Or is my FCB1010 broken?

Thank you in advance for your help