Hi laconnell
I'm not with Laminar Research, just a fellow simmer in the UK, but could you confirm if you are referring to the flap operating lever inside the cockpit, or the wing flaps themselves?
If it's the flap operating lever you are referring to, then having checked my version of X-Plane 11.35 and the default Boeing 737-800, then I am hearing reassuring clunking noises from the flap lever.
Having said that, I did need to go into X-Plane 11's sound settings to increase the internal cockpit volume, in order to hear the flap lever properly!
Regards