hi,
Sorry this could be a difficuly one, if you have already been to the experts. So maybe its bad to assume but you would think they have checked the obvious things.
is the driveline indexed correctly. Ie uni joints in the same plane?
Also, grease both fron and rear splines?
Failing these checks, best place to start would be understanding what was done during the lift. Who did it, and what did they do.
Was it replacement coils in rear and wind up the torsion bars at front?
if so, I would start by winding the front back down (can be done at home) until driveline angles back to original and test driving to see if it made a difference.