Well after the W10 updates last night I started AC on steam , and it initialised a first time installation setup of the game so oddWell, problem finally solved:
- removed the car
- downloaded and installed it again
- tried it and still no FFB...
- played a bit with FFB clip app and enabling / disabling Dynamic setting suddenly triggered the FFB.
It's great now. No idea what the exact issue was, (I was already blaming Win10 update )
All good now, thanks.