This gives me an indication that Do Not Disturb is on. (May be)
If you don't see notifications for a Messages
To get notifications, connect to a Wi-Fi or cellular network. If you still don't get notifications for a specific app, try these steps:
- Go to Settings > Notifications, select Messages, and make sure that Allow Notifications is on.
- If you have notifications turned on you might not have Banners selected. Go to Settings > Notifications, select the messages, then select Banners.
- Make sure that you’re signed in to your Apple ID.
- Make sure that Do Not Disturb is off.
To manage your notifications from the Lock screen or Notification Center:
- Swipe left over an alert or group of alerts.
- Tap Manage, then select from these options: Deliver Quietly: These notifications appear in the Notification Center, but don't show up on the Lock screen, play sounds, or show a banner or badge icon.
- Turn Off: This turns off all notifications for a specific app. To turn this back on, go to Settings > Notifications, select the app, and tap Allow Notifications.
You can also tap Settings to change your alert styles or alert settings for a specific app.
Use notifications on your iPhone, iPad, and iPod touch - Apple Support
https://support.apple.com/en-us/HT201925
