I just tried.  highlighting and pressing nvda numpad 5; while reading a thunderbird message body.  I have about the same result except NVDA says "section"."


I also tried while composing and got a slightly different result.

about:blank  document  focused  editable
" plus the line the cursor is on.


Just press numpad 5 alone, to read the word the cursor is on, and press twice to spell.


There was no problem using nvda+numpad 5 in the message headers.


version 2019.3 portable.

and

2019.1.1 installed.


Thunderbird  60.9.1


Bob