Samsung Galaxy Watch loses mobile connection after pairing to new phone

• You can only activate the mobile network for your watch with a phone running Android 5.0 and later with 1.5 GB RAM or higher, or iPhone 5 and later with iOS 9 or later. Activation with iOS and non-Samsung phones may differ by the carrier and may be limited or not supported at this time.

• To use the call or messaging features, the watch must be connected to your phone using the Galaxy Wearable app. Contact your carrier for a list of compatible phones, valid data plans, and NumberShare services. Make sure your account is in good standing.

When the watch is connected to a new phone, the watch will reset. During the setup process, you must complete the activation setup in the Galaxy Wearable app. You may be prompted to select the previous registered network to reactivate service for your watch, or to add a network.

• If you choose to cancel your service during the setup, you will be prompted to sign up for new service to activate the mobile network for your watch, or to skip and connect your watch and phone via Bluetooth.

• It may be necessary to contact your carrier or access your account to manage the phone number(s) associated with your account for the watch and phone.

• In some cases, restarting your phone should fix the problem. However, you may need to power off the phone, and then remove and reinsert the SIM card.
  

• If the mobile network for the watch is not detected during the setup, you may need to replace the SIM card for your phone or contact your carrier.

• Contact your carrier and verify that the SIM card inserted in the phone supports a mobile network profile for the watch. It may be necessary to replace the phone's SIM card and purchase a new data plan.

If you are still having issues getting your watch connected to a mobile network, your carrier will need to troubleshoot your connection from their perspective.