The patch is deployed and appears to be working. Our development team will continue to monitor the issue.
The issue only affected some users with some browsers that relied on built-in browser based autosaved passwords. In addition, users that used 2FA, or 3rd-party password tools were not affected.
The problem is related to browser-based auto-saved passwords injecting invalid login data during the login process. We have developed a patched and that has been deployed to PRODUCTION.
NOTE: 3rd party password utilities like LastPass are not affected.
Some users may have issues logging in. The issue seems to be related to auto-saved passwords. The issue does NOT affect the mobile client.
If you are having trouble logging in, try not using AUTOSAVED or AUTOCOMPLETE passwords, type in your password instead.