In older versions of Xojo, I found that RGBSurface.pixel on Windows builds to be unreliable… it would give wrong colors or simply not work.
I recently adopted the 2023 version in order to take advantage of the speed increases.
Suddenly I got a new bug - it went the other way.
Using graphics.pixel(x,y) to set a pixel color has stopped working,
but RGBSurface.Pixel(x,y) does on the same image.
Very strange, just putting it out here in case anyone else suffers from the same issue.