Hi
I can’t duplicate with Tumbleweed (no h 
) 20171010 GNOME 3.26.1. I connected to a never used before connection, no popup web page, connected and was able to surf the net etc…
If you create a test user, does it duplicate?
I’m guessing some sort of mime issue (maybe with FF 56?), but why it’s going where it is… if you fgrep in your home folder;
cd
fgrep -r "nmcheck" *
Any hits?