Cannot add user to custom role with scope room

Description:

When adding a new role with the scope: Room, users other than myself are not added to the list even though the "User Added" bubble appears when saved. This also appears to be a problem with an existing (default) role such as "Owner". The same "User Added" but nothing shows up issue exists.

Steps to reproduce:

1. Administration -> Permissions -> New Role
2. Role: testers with scrope Rooms -> Save
3. Choose a room
   4: Type in a user (other than myself) in the Add User field and click the ADD button
   5: ???

Expected behavior:

User to appear in the list similar to how users in a global scope role.

Actual behavior:

Nothing appears in the list. If I exit permissions, reload the Rocket Chat browser tab (or client), and look again, no users appear.

Server Setup Information:

• Version of Rocket.Chat Server: 0.70.0 and 0.70.4 (both from docker containers)
• Operating System: Centos (RHEL)
• Deployment Method: docker
• Number of Running Instances: 1
• DB Replicaset Oplog:
• NodeJS Version:
• MongoDB Version: mongo:4.0.0-xenial

Additional context

Relevant logs:

Start by reproducing the issue through Administration > Permissions using a Room-scoped custom role and a user other than yourself, on the affected Rocket.Chat setup. Trace the role and room user-add flow from that entry point; done means the selected user appears in the list and remains present after leaving and reloading the permissions view.