New watch pairs then unpairs during setup

Hey there cami10,

That's a very strange thing to occur. Let's start with confirming more details to better understand what's happening, along with ruling out some general things:

1. You mentioned that your watch pairs during setup with your iPhone, but then unpairs before the setup is complete. At which step does it unpair from your iPhone, and does it show any errors when this occurs on either device?
2. Sometimes unexpected behavior can be resolved with a restart: Restart your iPhone and How to restart your Apple Watch
3. Since you have a compatible iPhone model, the latest version is iOS 16.2. You can verify this within Settings > General > About. In case you needed it, this link shows how to first back up, then Update your iPhone or iPad.

Cheers!