administrator console, monitoring-alertmanager-edit user list or create silence, "Observe - Alerting - Silences" page is pending

This is a clone of issue OCPBUGS-1061. The following is the description of the original issue:
—
Description of problem:

grant monitoring-alertmanager-edit  role to user

# oc adm policy add-cluster-role-to-user cluster-monitoring-view testuser-11

# oc adm policy add-role-to-user monitoring-alertmanager-edit testuser-11 -n openshift-monitoring --role-namespace openshift-monitoring

monitoring-alertmanager-edit user, go to administrator console, "Observe - Alerting - Silences" page is pending to list silences, debug in the console, no findings.

create silence with monitoring-alertmanager-edit user for Watchdog alert, silence page is also pending, checked with kubeadmin user, "Observe - Alerting - Silences" page shows the Watchdog alert is silenced, but checked with  monitoring-alertmanager-edit user, Watchdog alert is not silenced.

this should be a regression for https://bugzilla.redhat.com/show_bug.cgi?id=1947005 since 4.9, no such issue then, but there is similiar issue with 4.9.0-0.nightly-2022-09-05-125502 now

Version-Release number of selected component (if applicable):

4.12.0-0.nightly-2022-09-08-114806

How reproducible:

always

Steps to Reproduce:

1. see the description
2.
3.

Actual results:

administrator console, monitoring-alertmanager-edit user list or create silence, "Observe - Alerting - Silences" page is pending

Expected results:

should not be pending

Additional info: