Arlene observed, "Confirmed! If you have a certain bug. Some people can or can’t confirm your bug."
Yep, because the number of variables that come into play to make certain bugs exhibit themselves are mind boggling (which is often why the software maker cannot replicate an issue even if they try to do so in what should be "the same environment" as it was encountered in by the user).
We have folks with various versions of Windows, all sorts of different hardware, all sorts of assistive technology beyond NVDA potentially installed, all sorts of programs in general besides NVDA installed, and the list goes on. Each and every one of those things has the potential to set things up *juuuuuust right* for you, and only you (or a very small number of people who have the same combination as you), to encounter a given bug.
I often think it's a bit of a miracle that most software functions at all given the number of variables at play that the developers have no control over and may have never even had a reason to conceive of.
I worry a lot. . . I worry that no matter how cynical you become it's never enough to keep up.
~ Trudy, in Jane Wagner's "Search for Signs of Intelligent Life in the Universe"