They should flutter a little, its how the car maintains the correct boost pressure.
Even the slightest hint of off throttle, and they will start to open.
If you really want to try lubrication, take them off, and try some wd40 straight down the guts.
Eg, where they plumb back to the intake.
Or try someone else's.
I'm running glad gtrs, and they constantly shuffle and flutter, could be the turbos if not stock.
Good luck.