Background Jobs still showing as inactive

bench enable scheduler (enabled for site1.local → the subject)
edited common_site_config.json “background_workers”: from 1 to 0;
bench build && bench restart
same issue showing as inactive.
Hyper-V VM, Ubuntu 18.04 LTS (with minimal gnome UI: sudo apt install gnome-session gdm3)
Installed Apps
ERPNext: v12.11.2 (version-12)
Frappe Framework: v12.9.1 (version-12)

edit: fixed.