I may have discovered what the problem was. Malwarebytes v4.5.14.210 detected and quarantined "PUP.Optional.Slimware" located at C:\PROGRAM FILES\MOZILLA FIREFOX\OMNI.JA. I restored OMNI.JA and launched Firefox in troubleshooting mode. Since it launched successfully, I turned troubleshooting mode off. Firefox seems to be working fine in normal mode, at least for now. Also note: I configure Firefox to advise when updates are available instead of automatic updates. This gives me time to research if others are having problems with the update. Since I didn't see any issues, I updated to 104.0.2 and thought it had been successful. After restoring OMNI.JA however, I learned Firefox was still at 104.0.1. I'm going to hold off updating to 104.0.2 again for a bit since the quarantine of OMNI.JA only occurred after the (apparently unsuccessful) update.