I assume you are rotating a few degrees to align a horizon or something. You need to use the correct tool which is called straighten Horizon. That will rotate as you set the stretch band, and auto crop the white.

Fred

See screen snap

Toward the lower part of the screen snap, it says, Rotate 0,0.
Just to the right of that is a slanty yellow little icon. Place your mouse pointer on it, it should say, Straighten Horizon.
Click that.
You now have a cross pointer.
Find the left end of the horizon, or if a vertical is available, find top or bottom of a column, and click, That's the start point.
Walk the mouse with the elastic dragging, to a point to the right side of the horizon, and click.
Qimage will make the string line you created as the new horizontal level, rotate the image and crop the white exactly where it should be cropped.
If you need better screen snaps, let me know.

Fred

Was that when it was only for Nikon files?
It has come a long way since then, especially in QU in recent weeks.
Terry