Not Happening

I noticed the, ah, alteration to this sign while walking with my wife today. The Featured Image is the second of two pics captured using Sigma fp and 45mm F2.8 DG DN | C lens. The first, auto-focused, isn’t. This other is manual and spot on—and the mechanism making it was smooth-using. But auto consistently causes me grief. Right now, one—sometimes two—out of three shots is off the intended focus point. Looks like, in the default setting that I haven’t changed, the camera chooses closest thing, even if nothing—as is the case with the sign scene (not shown here).

Photo vitals, aperture manually set: f/5.6, ISO 100, 1/1000 sec, 45mm; 2:01 p.m. PST.