I watched a 1 hour video on the FBW, but at no stage did the flier use the heading knob.
I assume you mean use the mouse to ‘pull’ it?
I have a left & right button mouse with the wheel between them. Despite my best efforts using all of the mouse buttons & wheel, I can’t pull the heading knob out. When I hover the mouse pointer over it I get that blue halo over the knob, & that turns yellow if I click on the knob or use the wheel to turn the knob to alter the heading…
I’ll keep looking at videos. 
T45