Just went through this with a new pistol. I set up a nice, solid rest and took my time lining up the sight picture. First shot went into the bull, next four clover-leafed with it, proving that it was me rather than the sights.
On the other hand, a few years ago, with a different pistol, the same test showed the rested shots to also be left and just a bit low. A quick tweak of the sights and all was good. For me, you can’t beat a good rest for diagnostics.
For me the diagnostic is RSO. Every new pistol I shot brought some accuracy issue… too low, too high, slightly left, sometimes right.
I was always upset about it and asked RSO to put some round downrange… he was always dead center 
When there’s nobody to help me, I reverse the grip, shooting like right handed and everything magically comes back to normal…
99% of my pistols were zeroed correctly out of the box.
Grip and trigger control are the key.
I believe that was yuan two manknee smiley faces… I believe that is proper troll language… might be my Indian name. I will ask Pocahontas… 
Just move the target an inch or so to the left. Tada. You’re welcome. 
I sued the target manufacturer because the targets were printed off center.
Fun fact: Early military targets were oblong to compensate for the bullet drop. This was reflected in the early Distinguished shooter medal.