Left part of image is often more blurry. Why?

[snowbear]

I have the same problem too with my Nikon-Fit 17-70mm Sigma lens. My photo is slightly blurry on the left side. I bought a new Nikon D7200 camera body and the result is still the same. I don't know what's causing it which is so frustrating.

You realize the quoted comment is three years old and the BLOEPPKY never posted anything else?

Post an example with EXIF and we might be able to help you figure it out.