Add comments button missing after implementing SSO (custom authentication)

Hi,

We have implemented Custom Authentication to enable SSO using extension on the link Microsoft has provided below

https://github.com/microsoft/Reporting-Services/tree/master/CustomSecuritySample2016

However, ever since we made changes on the server, the "Add Comments" button is missing from reports. We checked all the roles and ensured that Add comments section is enabled. we still cant figure out why the button is not visible to any user irrespetcive of their roles.

The reposrt server version we are using is 1.8.7485.35104 (May 2020) and the poer BI desktop versio is May 2020.

Have any one faced similar issue? any help is really appreciated

Regards

Sanjay Shenvekar