bug#56662: 29.0.50; Funny region highlights when highlight-nonselected-windows is t

[Eli Zaretskii]

> From: Visuwesh <visuweshm@gmail.com>
> Date: Wed, 20 Jul 2022 17:05:11 +0530
> 
>     1. emacs -Q
>     2. Visit a longish file.
>     3. C-x 3 and scroll up in any of the window.
>     4. M-: (setq highlight-nonselected-windows t) RET.
>     5. Create an active region and compare the highlighting.

What is wrong with this behavior?  In each window the region between
the mark and point is highlighted, as you requested by turning on that
option.

What am I missing?