RHODS Admin page keeps showing users who lost permission access

Description of problem:

If a user who spawned a notebook loses the access permissions (e.g., a change in allowedGroups setting of dashboard), its username keeps appearing in the Administrator tab of KFNBC. This allows an admin to spawn a notebook for the user which shouldn't be allowed anymore to spawn servers.

It doesn't happen for users who have never spawned a server earlier and then lose the permissions.

Prerequisites (if any, like setup, operators/versions):

RHODS Admin access

Steps to Reproduce

1. Access KFNBC using a RHODS admin
2. move to Administration tab
3. spawn a notebook for a userA and then stop it
4. remove access permissions from userA (e..g, change the groups setting from dashboard or remove userA from an allowed group)
5. go back to Administration tab
6. try spawning a server for userA

Actual results:

Admins is allowed to spawn a server for a user who has lost permissions

Expected results:

Admins shouldn't see users who lost access permission to KFNBC and shouldn't be able to spawn notebook servers for the same users

Reproducibility (Always/Intermittent/Only Once):

Always, unless the users who lost permissions have never spawned a server earlier

Build Details:

RHODS v1.16.0-6

Workaround:

Unknown

Additional info:

None