With OWS 1.9.6, the log contained a number of these:
/app/lib/python3.12/site-packages/affine/__init__.py:515: RuntimeWarning: invalid value encountered in multiply
return (vx * sa + vy * sb + sc, vx * sd + vy * se + sf)
Don't get any more useful context in the log than this, but I'm guessing the invalid value is a NaN.