Yes, this has been reported a few times. I believe it's Fx bug which should deal with site's coding and TMP should to, IMO. They both need to respect the option setting but they don't. There are gazillions of bugs filed on
Bugzilla, you can do a search or search here (button at the top of the page) to find my post with a link to the list of those bugs (sorry, have no time right now) - BTW, the search on this site will open in the current tab , just so you know
Here's Bugzilla results
for Google related bugs, you can search from there for a new tab ... or whatever. Some say you can set this in Google prefs (won't work for me as i don't sign in and don't keep their cookies) if interested, search this forum.
Found it,
here.
Sorry, forgot to say, Mclick on a link should open it in a new tab. Not ideal but a workaround.