I have the same issue described here: https://support.mozilla.org/en-US/questions/1387715. However, the accepted solution was not the answer for my situation, since the ownership of the ''~/.local/share/'' directory was correct on my system. In my case the slow start-up resulted from the ''xdg-desktop-portal-gtk'' service failing to start because of '''DISPLAY''' setting issue. This was a difficult issue to debug, since the console wasn't showing timeout errors resulting from Firefox not being able to communicate with the ''xdg-desktop-portal-gtk'' service. My fix was is elegant, but works: # Edit ''/usr/lib/systemd/user/xdg-desktop-portal-gtk.service'' and add the line ''Environment="DISPLAY=:1.0"'' under the "[Service]" line. # sudo systemctl daemon-reload # systemctl --user restart xdg-desktop-portal-gtk # To get the service to start correctly every time I start a VNC server, I also added this line (systemctl --user restart xdg-desktop-portal-gtk) to my ''~/.vnc/xstartup'' file While I think this solution will continue to work, because my DISPLAY is always :1.0 when I use Firefox, I would rather have the ''xdg-desktop-portal-gtk'' service figure out the correct DISPLAY setting. Are there any suggestions on how to do that? Or, is there a way to configure Firefox to not rely on this service?