A few weeks ago I purchased a MacMini M4 and am unable to login to sync. MacOS and Firefox are up to date. When logging in to Firefox sync, I enter my email address and then password. I'm then prompted to enter the code sent to my email. I enter the code. I'm then prompted to enter the MFA code from my authentication app. I enter the code. An error shows up that says unable to process. I also deleted the Firefox app and the app data and reinstalled several times. I've tried logging in via Private Browsing. Nothing seems to work. I don't have any extensions installed or other applications or unnecessary processes running.

I have successfully logged into a MacBook Pro, a gaming PC desktop, an HP Windows 11 laptop, and a couple Linux devices and VMs...so I'm familiar with Firefox - been using it for forever. This is the only computer I can't seem to log into. Any suggestions for troubleshooting would be helpful. Thank you.