Nauticam 140mm FE Dome Question

I'm using the Nauticam 140mm FE dome with the Canon FE 8-15/4 in combination with the two RF extenders and I've noticed that when zooming out, the lower right corner of the dome's lens hood is always the first part of the image to appear.

There's an inaccuracy and I don't know the cause.

It could be due to the lens hood's manufacturing, or perhaps the camera's position in the housing isn't perfectly precise—or a combination of both.

Has anyone else noticed this?

It's not a major issue, but it does reduce the FOV somewhat.