If you receive an error while signing into your school email and you're using Apple's Safari browser please temporarily use Google Chrome to access it. Microsoft is aware of the issue (Issue reported on the 6th by another tenant) and is actively working to resolve it.
You can readily identify the issue if you watch your address bar and see it repeatedly try to load the same address over and over until you're dropped back to the sign in page.
Please note this is a temporary and specific issue. Password input errors don't apply here.
This issue has been resolved as of 12/10/19