The crossed-out circle at the top of the Samsung Galaxy screen usually means that the phone is not connected to a mobile network. In its manual, Samsung describes this symbol as “no signal“. In such a situation, calls, SMS messages, and mobile data may not work.
This is not an icon that can be manually removed from the display. It disappears when the phone reconnects to the carrier. The first check is at the top of the screen or in the quick settings panel, where you should see if “Airplane“ mode is turned on. Samsung specifies: “Airplane“ mode turns off all network connections“. To turn it off, open Settings > Connections and turn off the “Airplane mode““ switch.
How to restore signal
If “Airplane mode“ is off, restart your phone. A temporary software or network registration issue may be resolved after turning your device back on. Also, make sure you're in a location with coverage, as the signal can be weak or absent in buildings, underground spaces, and remote areas.
The next step is to check your SIM card. Go to Settings > About phone > Status information > SIM card status and see if the carrier name is displayed. For a physical SIM card, the phone must be turned off, the card must be properly inserted in the tray, and its contacts must not be damaged. For an eSIM, the profile must be active. Samsung states that an incorrectly inserted, damaged, or unrecognized SIM card can stop mobile connectivity.
If the problem persists, you can reset only the mobile network settings from Settings > General management > Reset > Reset mobile network settings. On some models, the menu is labeled “Reset network settings“. Samsung warns that the names and locations of the menus vary by model and software version. Resetting may remove saved network configurations, so you may need to reconnect to your mobile carrier afterward.
Not to be confused with “Do Not Disturb“
On some models, a similar symbol may be confused with the “Do Not Disturb“ icon. It does not stop the mobile signal, but silences calls, notifications and alerts according to the set exceptions. It is turned off by swiping down from the top of the screen and tapping the “Do not disturb“ button, or from Settings > Notifications > Do not disturb.
If the crossed-out circle remains after restarting, checking the SIM card and resetting the network settings, the cause may be an interruption at the operator, a damaged SIM card or a problem with the phone. Samsung recommends in this case checking through the Samsung Members app, in the mobile network diagnostics section, and if necessary, contacting the operator or service.
Sources: samsung.com