Unable to access system console, permission error in log

Thanks @traxwriter for the response,

1. What database (and database version) are you using?
2. What version of Mattermost (and GitLab) are you on?
3. If you sign into your Mattermost instance with the account, do you see "System Console" as one of the Mattermost main menu options (from three-dotted menu)? To confirm the role was successfully switched.