Microsoft found the issue and reverted back an update they made. Here is their official statement:
"We identified that a recent routine update to a portion of the Microsoft 365 navigation service introduced an issue that causes inconsistent user provisioning detection, resulting in affected users being incorrectly redirected to a fallback page. To remediate this, we’re reverting the offending change and monitoring the service to ensure successful remediation."
OneDrive and SharePoint through https://office365.uiowa.edu/ are unavailable. Users are receiving a redirect error, Microsoft has been notified.
In the meantime, users can go to "https://iowa-my.sharepoint.com/" to access their OneDrive online. They can also go to "https://iowa.sharepoint.com/" to access their SharePoint online.