Not really a problem - but rather a fix to an annoyance - Default Mail Client
I've been using Firefox when it was sort of called Netscape Navigator and its Mozilla's companion mail client - Thunderbird.
So it was a bit annoying (but easily corrected, of course) that Mozilla would undercut it's own products by changing the Thunderbird as the default mail client in favor of something that resembles Microsoft - after a couple of decades of use.
Just noting
I've been using Firefox when it was sort of called Netscape Navigator and its Mozilla's companion mail client - Thunderbird.
So it was a bit annoying (but easily corrected, of course) that Mozilla would undercut it's own products by changing the Thunderbird as the default mail client in favor of something that resembles Microsoft - after a couple of decades of use.
Just noting