Why is there a red X on my Apple Watch face? How can I turn off the red X on Apple Watch?
The Apple Watch Series 3 and later offer a model with cellular data connectivity. This reduces the need for Apple Watch to rely on a nearby paired iPhone or Wi-Fi network to make calls and send messages. GPS + Cellular models feature a red ring on the Digital Crown to indicate cellular capabilities.
Using a cellular network with Apple Watch requires a data plan subscription with a wireless carrier. Some areas may lack cellular data coverage, leaving the Apple Watch disconnected from the network.If the red "X" icon appears on the Apple Watch face, the device has lost its cellular network connection. You can verify cellular network signal strength and connect to Bluetooth / Wi-Fi / Cellular data from the watchOS Control Center. Contact your wireless carrier for additional support.