Does it still show that message with a random username/password?

Try clearing site cookies and disabling Tracking Protection for the site.

Does it still happen in Troubleshoot Mode?

I've cleared cookies I added usaa.com and the logon address as an exception enhanced tracking protection can't be turned off, but it is set to standard troubleshoot mode did not help I can access the site from my laptop and my phone

Does it still happen in a new profile? An easy way to test a new profile is to install Developer Edition and see if it happens there or refresh your existing profile. Make sure you stay signed out of your sync account when testing.

I think that I previously refreshed the profile. I have a profile that I no longer have access to because Firefox won't reset my password and the current profile is always disconnected. I downloaded the Developer Edition and I can log into USAA. I suppose I can just use that instead of regular Firefox.