Don’t tell anybody, but I installed Google Chrome in order to ask this question. Thanks for your tip. It does sound like similar problem. I do not get any error notification but I do get warned about process still running when I shutdown or restart Fedora.
I’m having same issue. I even re-installed F37 from scratch, and after the default install. Firefox won’t sucessfully start. Creates a few processes, but fails to display. I have to pkill -f firefox to make it stop. So I had to install Chrome to post this message.