I can say installing thunderbird-gnome-support fixed this issue for me.
http and https links now open on their own in Firefox, which is set as me default browser in Preferred Applications (with "Open link in new tab" as an option).
I can say installing thunderbird- gnome-support fixed this issue for me.
http and https links now open on their own in Firefox, which is set as me default browser in Preferred Applications (with "Open link in new tab" as an option).