Vrs Mk1 turbo issue

Hey guys ! new in here.. 

Tried browsing for this, but couldn't seem to find it anywhere... 

Been having a turbo  issue lately.. 
Sometimes when I start the car, the turbo won't really put out any pressure... after I kill the engine and start it up again it works completely fine.. 

Thought it might be the diverter valve not functioning, swapped the oem plastic one with a metal one.. still the same issue 😕

cleaned maf sensor, turbo sensor.. none of that worked.. and it really puzzles me, since the car only needs to "restart" and the turbo runs fine"ish" again... 

Hope some of you might have had this problem before, and fixed it