Zoom position lost.

[FKCapitalism2]

Open image full sceen
select fit image to window
position mouse cursor in middle of the image
click and hold left mouse button to zoom it 100%

Notice you can use mouse (while holding LMB) to pan around

now while holding LMB press + button on keyboard to zoom in two or three times.

Now try to pan with mouse again and panning jumps off the position you were and goes into upper right corner of image.