Tapered fork steerer tube measurement
This is what it was purported to be. The crown race seat area where you're measuring should be more like 33.03-33.09mm (or around 1.302") but I suspect you're not pulling the caliper quite tight enough when you take the measurement. 

Originally, though they've never been a common size, there was such a thing as a 1-1/4" non-tapered steerer tube. If you had one of those to measure, you would find the diameter of the steerer was indeed 31.8mm/1.25". But the crown race area down at the bottom is always a little larger. What's confusing here is that because of how the taper has been done, there really isn't a straight 31.8mm/1.25" section to measure.

All that said, this fork is mostly only useful as a replacement for certain CAAD and Synapse models. It won't fit many other bikes.