Thanks both - really appreciate the advice. I have checked with MIDI Monitor - no dice. So therefore the FCB - recalled seeing something somewhere about initialising so followed the steps here:
https://www.sweetwater.com/sweetcare/articles/the-expression-pedals-on-my-behringer-fcb1010-midi-foot-controller-dont-work-properly-in-programming-mode/
Which has worked a treat - all good now. I bet this is in the manual (Uno2 and/or FCB1010 manuals) or on the website somewhere - classic RTFM issue ;)