What it means — Apple
When your devices aren't connected, the red iPhone icon or the red X icon appears in Control Center. When your Apple Watch connects again, the green iPhone icon appears.
If you don't get notifications, messages, or calls on your Apple Watch, your Apple Watch and iPhone might not be connected.
What to do — Apple
- 1 Bring your Apple Watch and paired iPhone close together. If your watch shows that the devices are still disconnected, try the steps below. After each step, see if your devices can connect.
Read the full article for pictures and model-specific details: If your Apple Watch isn't connected or paired with your iPhone ↗