Why is Firefox opening a new window instead of a tab from an external link?
When I open a new link from an external source (Thunderbird) this is what always happens: 1. Firefox 72.0.2 (64-bit) is already running: I get a new tab in the current open window just as I have set it - great! 2. Firefox is not already running: It launches and I get a first window with the home page and a SECOND window with the link - HATE!
I want example 2 to behave like example 1.
I have the correct tab settings in preferences I have played with the settings in about:config (browser.link.open_newwindow, etc, etc) and I cannot change this behavior.
I am running Mac OS Catalina version 10.15.3 (19D76) (latest).
Additional System Details
- User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:72.0) Gecko/20100101 Firefox/72.0