Outlook Web Access stopped working after CloudFlare implementation

Outlook Web Access stopped working after we moved to CloudFlare. Users used to be able to go to web.domainaname.com, but now they receive an error message. The CNAME for web.domainname… is in CloudFlare, so not sure why they can login.

The error message they receive is: AADSTS50011: The reply address does not match the reply addresses configured…

Login into MS Office works fine, but not when directed via web.domainname…