Having issues with Firefox 67. Starting the application takes around 1 minute. When starting Firefox from the gnome dash bar, KSysGuard reports 2 Firefox processes one of which is tagged as zombie, which goes away once the application is 'ready'. This behavior was manifest even on a fresh installation with no extensions and default settings. Launching Firefox from the terminal opens 2 processes, one is a zombie process, the other is tagged as 'disk sleep'. Eventually the app gets ready.
Closing the app reports this in the terminal
###!!! [Child][MessageChannel] Error: (msgtype=0x530005,name=PHttpChannel::Msg_Cancel) Closed channel: cannot send/recv
8 GB ram