Turbo actuator vacuum loss normal?

Got a limp home issue with the P2263 fault code showing. Trying to diagnose this, so check the hoses from turbo to intake manifold, all fine. Take out and clean the MAF, IAT and MAP sensors, plugging them in one by one to see what faults come up, seems fine. So under the car I go to check the turbo itself and seems ok, little oily but assume it's from the breather hose (catch can now fitted and hoses and intercooler cleaned with carb cleaner), but compressor spins with no play, takes a little bit of pressure to spin it but it's smooth. Start going through vacuum hoses with a vacuum pump, no probs. Try pulling a vacuum on the turbo actuator and actuator arm does move freely, but immediately loses vacuum and arm returns original position. Shouldn't it hold vacuum and arm remain in position until vacuum changes?

I'm reasonably handy guy, but this is a little out of my purview, so any help appreciated!

It's a '07 Focus 2.0 TDCI 136bhp/100kw version.