Just a heads up in case some others run into this situation.
After installing Firefox v184.108.40.206 I found that it would not connect unless I disabled ZoneAlarm. Looking at the ZA logs, sure enough, ZoneAlarm was blocking it. I checked the Program Control setup for Firefox and it had the access rights it needed, but oddly there was no green dot in the "Active" column even though I had the program open. IE worked, so I came to check this forum and noticed there was a new version of ZoneAlarm (7.0.462). After doing the update, whatever the issue was with Firefox, this fixed it.
Operating System:Windows XP Pro
Product Name:ZoneAlarm Pro