Gene,

          I believe your latest suspicion is probably correct.  I found the same thing that you did if I selected when Focus Highlight showed me to be in browse mode with a thin, green dashed line indicating the navigator object selected.  When this was text of any kind I'd get straight text - formatting was not retained.

          I used the methods I document here:

• Selecting Text Using Windows Keyboard Shortcuts

once I've got myself positioned where I want to be, or at least roughly so, I really don't know how screen reader users ever get precise positioning in masses of text easily, as I'm certainly crappy at doing so using only the keyboard.

If I select that way all formatting, and additional content if  the text is interrupted by an inline image, is retained and pastes perfectly.

Someone else who's a better NVDA user than I am can test the details out.

--

Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134  

    A little kindness from person to person is better than a vast love for all humankind.

           ~ Richard Dehmel