M20K dripping turbo

I just got both check valves replaced on my M20K-262. Things clearly got better, but not good.

When I found a little puddle of oil under my exhaust the next day again, I was ready to puke. My understanding is that every drop of oil going into that turbocharger must first go to one of the two check valves.With now both check valves new, this leaves me with "unlikely" solutions only:

1) brand new valve is bad

2) if the valves would have been put in incorrectly from the beginning, chances are my mechanic would have put the replacements in the same spot. I am not talking attached to the wrong oil line, I am talking too close to the turbo, at an angle instead of vertical etc.etc.

Has anyone had a similar experience?

Can anyone share a picture of correctly installed check valves in a M20K-262?

Thanks in advance for your help:

Juergen