Users will appear in any user picker and in mention (@) even if they don’t have application access at that time but only if they don’t have “Jira Administrators” or “Jira System Administrators” permission!
Users with “Jira Administrators” or “Jira System Administrators” permission
Users who has “Jira Administrators” or “Jira System Administrators” permission won’t appear in the user picker and in mentions while the License Optimizer is active and the user doesn’t have access at that particular time.
Workarounds
Check who has “Jira Administrators” or “Jira System Administrators” permission and make sure all of them actually should have this permission.
Add Users or Groups with “Jira Administrators” or “Jira System Administrators” permission to the application access menu.
Create separate account for users that should have “Jira Administators” or “Jira System Administrators” permission and add this accounts to the perrmission. The users will be able to switch account if any of their action requires administrator permission.
Create one “Jira Administrators” user and grant access for employees who needs it.