The "moon" icon in the status bar indicates that the phone has turned on the Do Not Disturb mode. If you do not want to display this icon, please turn off the "Do Not Disturb" mode.
Setting path: Settings > Search for "Do Not Disturb" > Turn Off Do Not Disturb
Note: In the case of Do Not Disturb mode, the message notification will not be displayed on the screen, and the message will not be displayed until you light up the screen.