3-point perspective problem

I have discovered some strange behavior in the outermost lines that converge in 3-point perspective.

This pertains specifically to those lines that form the vertical convergence; i.e., the vanishing point that is way up high above the image.

So, when I grab the handle to move the left outermost line, the line itself disappears maybe 20% from the left edge of the image.


The handles are still there, but the line is gone.

Then, when I move this left line rightward, the line reappears! It's as if something is hiding it if it moves too far left.  Strangely, the RIGHT outermost perspective line for this same VP stays visible at all angles.

It seems like a bug to me, but maybe there's a logical explanation.

I'm open to any guidance you may have.

Cheers from Houston,


Windows 10 Pro, Painter 2022