Image hard crop no longer working as expected

[WorldWideWebb]

Since I upgraded to 4.2.1, hard cropping of images no longer seems to work (resizing always occurs using soft-crop mode, resizing the larger dimension first, then cropping the smaller to size). I am regenerating them using the regenerate thumbnails plugin (which works fine), and am looking at the images directly on the server (FTP) to eliminate the possibility that any CSS might be producing strange results. It is a custom theme that I built, but I switched the site over to Twenty Fourteen to rule out my code and got the same results. I also tried disabling plugins, to no avail.

I am running my production site on the same server (which is running 3.8.7) and the crop works fine.

[MarcGuay]

It might help to attach example images of the behaviour you're experiencing.