I'm receiving this same issue. I've tried upgrading to 9.16, as well as downgrading to the latest stable release of 9.14. I've regenerated the AzureAD certificate. I've verified all configuration steps with both the Cisco documentation and the Microsoft documentation. This was working with no issues, then just randomly started having this issue. It then went away and functioned normally for about 3 days and now is back to the false CSRF errors.