Monitors do not show up even I assign all the privileges

Plugins Alerting
1

I am running ElasticSearch on AWS v 6.8 with SAML authentication and fine-grained access control. I restored .alerting indexes from another cluster and as an admin user, (access_all) I can see all the monitors. To allow other users to see all the alerts and monitors, I have create a role with all cluster:admin/opendistro/alerting/* permission. I also provided access to the .open_distro index.
The problem is, when user connect to Kibana and select alerting, he see all the alerts but not monitors.
If he issues request to _opendistro/_alerting/monitors/ he see 404 response code. As an admin, I see the monitor correctly with this API.

How can I give a user access to see and modify the monitors or it’s not supported in 6.8?
Here is my roles for the user:

"alerting_full_access" : {
    "cluster" : [
      "CLUSTER_MONITOR",
      "cluster:admin/opendistro/alerting/*"
    ],
    "tenants" : {
      "Global" : "RW"
    },
    "indices" : {
      "*" : {
        "*" : [
          "INDICES_MONITOR",
          "indices:admin/aliases/get",
          "indices:admin/mappings/get"
        ]
      },
      "?opendistro-alerting-alert*" : {
        "*" : [
          "CRUD"
        ]
      },
      "?opendistro-alerting-config" : {
        "*" : [
          "CRUD"
        ]
      }
    }
  }

I mapped the user to that role.