Cloud REST API's not returning the full list Role-bindings

Cloud REST API’s not returning the full list of role bindings in the organization. I am using the cloud API key here.

I can read the other role-bindings, but when I try “get” to full list, it is only returning 11 role-bindings. I am setting the page_size=100.

Is it a known issue? As I am using “cloud-ApI key”, I am expecting to see all the role-bindings in the organization.