401 error after Identity upgrade

Summary:

Has anyone else experienced a 401 error (www-authenticateBearer error="invalid_session", error_description="Authentication Failure") with the update? After clicking a link to a learning item, some users get the 401 error immediately after clicking SSO. However, if they click the link a second time, it works every time.

We are using Microsoft ADFS. Our IT team confirmed that all production links and settings are configured correctly in Relying Party Trust. They also reviewed many log files and found no signs that users were being redirected to lower environments from production.

We have a very important mandatory training to launch but it's been put hold until this issue is resolved, so I'd greatly appreciate any insights!