On an Ubuntu 17.10 system currently Google Chrome (installed via deb) is my default browser.
I installed brave browser with
snap install brave --candidate then launched it from the command line.
As expected brave launches and asks to be made the default.
I say "Use Brave". I then try clicking a link but this launches in chrome, the previous default, not Brave.
Checking my desktop defaults in system settings, it looks like the button in Brave didn't actually set itself as the default.
Indeed it doesn't even appear in the list:-
Is this an Ubuntu desktop bug, a brave bug or a snap bug? Or perhaps all three?