OK yeah we found the weak logic… we assume the FIRST camera that’s chosen for a device after you start 1.7 is the CORRECT camera. That was silly.
That initial choice is when the cameraSizeX and cameraSizeY settings get backfilled, and if they’re wrong (because you picked the wrong camera, even briefly) that causes the crazy warping… which you can’t fix without reverting those settings.
I’m working on a bugfix that will provide an option to “reset” old calibrations to the current camera, so you can remake that choice after-the-fact. Hopefully that will be released within days.
Until then, a bad solution is to edit the camera settings JSON file to set the correct resolution (as I tried to do) and re-import.