Firefox will not start unless I specify --display=:0.0

Support
1

Description

Several weeks ago Firefox stopped opening when I try running it using normal methods (Super → “firefox” → ENTER).

FF will only start if I specify a display when executing from the terminal:

firefox --display=:0.0

If I open FF any other way, no window will display, however a new process does appear to run. It used to be “Firefox” but as of yesterday, it is now just "GeckoMain"

Additional details

If I click on a web link somewhere in the OS (GNOME Terminal > Menu > About > Website, for example) I get the following:

Screenshot from 2021-10-06 10-44-08
Screenshot from 2021-10-06 10-44-08736×152 16.5 KB 

$ firefox --full-version
Mozilla Firefox 93.0 20211005175701 20211005175701

$ echo $DISPLAY
:0

$ which firefox
/usr/bin/firefox

$ cat /usr/bin/firefox
#!/bin/sh
exec /usr/lib/firefox/firefox "$@"

Troubleshooting

I’ve tried:

2

Is the display specified on command line different from the one in $DISPLAY?

3

Same.

$ echo $DISPLAY
:0
4

Any info as to why the browser engine is now the process name?

5

I can’t really say as to why. I don’t know what happened that made it do that. Some update perhaps?

6

Update: If I choose “Gnome classic” at the login screen, Firefox launches like normal. However it still appears as “GeckoMain” in System Monitor.