Got Access Denied when viewing On-Call Role schedule

When editing the On-Call Role schedule by clicking the + button on the page below, it returned Access Denied even though I was logged in as admin. No change in spring security. Tried logging out and in. I had not encountered this issue before upgrading from 27.1.0.

Steps to reproduce:

• Click on Configure Users, Groups and On-Call Roles

• Click on Configure On-Call Roles

• Click on Add New On-Call Role

• Add a name

• Change Membership Group if you want

• From the "calendar" view, click on the plus button on any day.

• You get the Access Denied, and you shouldn't.

page url:

<OPENNMS-SERVER-HOSTNAME/IP>/opennms/admin/userGroupView/roles