Habs always had off, but by resetting to factory settings, it's back. Unfortunately forgot how the switch off is.
Go into the settings, then search for notification bar above and then simply turn off the switch for mobile service providers.
Sorry no! The menu item Display I do not have!
If you still have no answer:
Settings → Apps & Notifications → Notification & Status Bar → Show Network Operator Name → Close Settings
If you do not have any point, sry have Android 8.1.0.159