Could be... How old is the LBE? Take it apart and inspect the plastic plunger and rubber O-ring. These can get deformed over time by heat and cause binding in its travel. Clean the oil and any crud that' accumlated.

To rule out the CV, run a new hose directly from the outlet of the LBE straight to the wastegate. Don't use that silly thin 1/4" blue-silicone hose. Get some real thick-walled rubber hose, 1/4" ID and 1/2" OD should do.