Thanks for this Hope.
I don't use the numpad insert though. I'm using a full sized USB external
The only time this problem occurs for me is when the machine is heavily
loaded and labouring with a large number of open firefox windows.
There would be a couple of seconds delay after hitting Insert-f12 and then
the dev console appears as if NVDA has missed the keystroke and it's been
passed through to firefox instead.
Now I know I just need to hit f12 to switch back again, that won't be a