Hmmm....after some investigation it might not be the shift lens, but my material picker is still offset. Also probably related -- but the bottom of my image doesn't show in the octane render window but when I export an EXR it's there. The bottom of the image is also visible in the modo viewport, obviously.... Hmmm time to restart modo. Ok still having the issue after a restart. Perspective correction is off, so it's not that.
I have previously been using shift cameras in my scene, but the camera I'm using now doesn't have shift.
So basically my Octane render viewport is cropping the bottom of my composition of, but not during export, this is also offsetting the material picker. I'm stumped maybe it's not a bug and im just doing something wrong. I can work round it but maybe worth looking into.
See the red line in the image below.
https://imgur.com/a/xhucGpL