As can be seen from the thumbnail shot and the screenshot, the camera is offset, and it may have something to do with the place of the orbit.
The screenshot was taken in a rough polar orbit. The camera was highly offset from the CoM. To test that it has got to do with the orbit planes, I changed the inclination to roughly 30 degrees, and the camera began to slide more to the CoM of the craft (see thumbnail shot). The is no camera-auto-realign button at the top left, which means I didn't slide the camera with right click (I'm not sure how to hide the flight menu to prove this).
What is expected to happen:
Camera should point to the CoM at all planes.
What actually happens:
Camera begins to slide off the CoM with increasing inclinations.
Edit: It seems to happen not 100% of the time. I realised the camera was fine at one point in the same inclination, and it got offset when I staged.
@AndrewGarrison in the sandbox I linked it should be just a matter of loading it, it's not as extreme as what can be seen in the original sandbox thumbnail but the craft is way smaller too.
Maybe the
Screen position out of view frustumerror is related?