Just replaced an Apple Watch 5 with the new Apple Watch 9 (both with cellular). All went smoothly until I checked my Verizon account and the new watch is showing with all the correct device ID/IMEI, etc. but it is showing as a non registered device and also showing that it is eligible for an upgrade. Of course, the ridiculous AI chat is useless and attempting to talk with a live operator is impossible. I signed up to be called back and, of course, that is a two day wait. After decades of using Verizon, it's customer service has gone completely downhill. Still waiting for my call-back!