randomly not changing from P to drive/rev,no matter cold or hot,computer scan ok

What is your question?

Computer scanned many times and reset,no codes of malfunctioning identified.After start engine,not always,cannot change to drive neither reverse,after engine turn off,and restarted then shift accepted,sometimes after one try,and others after two/three tries.All equipment is working,no leaks,nothing wrong identified.Mechanic has no thing to do.Any idea?Thanks!

What makes this problem better or worse?

Nothing

How long has your 2013 Mercedes-Benz ML350 had this problem?

Months