I've encountered https://finance.yahoo.com
Well this one is wierdly broken. Firefox on Windows (44.0.2) works fine.
Firefox on NetBSD 7 also 44.0.2 gets the mobile site. So this isn't so
much a firefox issue as a firefox NetBSD issue that's very specific to
this site. Have you made any attempt to talk to them about it?
Even more weirdly when I hit that site in Microsoft Edge I get a link
promoting Firefox!
The google one seems to think I'm browsing with chrome and doesn't offer
a chrome download but apart from that it renders the page fine and has
exactly the same content as the windows version of firefox.
My firefox builds are:
Build identifier: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:44.0)
Gecko/20100101 Firefox/44.0
Build identifier: Mozilla/5.0 (X11; NetBSD amd64; rv:44.0)
Gecko/20100101 Firefo
x/44.0
Mike