P0299-Underboost-2.0TDI 110KW DSG

in August I had 4 times P0299- Underboost. Car goes to limp mode with Error: Drive System. Turning car off and on deletes the message and car drives normally after that.I did 1000km after the last error with no problem . I asked VW workshop to do diagnostics and they said that its a actuator broken and that I need new turbo as only actuator cant be replaced. I logged live data in CarScanner Pro for Turbo position with variable geometry request and actual and there are no differences. Did anyone have that problem and did you had to change whole turbo( Prices is insane they are asking for 4000 euros)