Apple watch cannot pair
I bought a new Apple Watch 4 for my mom. She couldn't pair it with her iPhone 7 plus. When using camera to pair it, it will show the pairing fail. When using manual pairing, the phone can find the watch but there are no 6 digits password show up on her watch. Bluetooth and WiFi are both turned on. iOS on her phone is 12.2.
I used my Apple ID when I purchased the watch online. Not sure if this causes the problem.
Apple Watch Sport