What do I do if calls disconnect automatically?

Please try the following:

1. Turn Airplane Mode on and off, and then dial again.
2. Go to Settings> Network & Internet> SIMs> Enable 4G Calling or Disable 4G Calling to try again.
3. Change the network environment and call again.
4. Try a different SIM card.
5. Update the phone's software to the latest version.
6. Back up any important data and restore your phone to factory settings.

If the issue persists, contact the Nothing Support Team for further assistance.