Apple has found problems with the component that powers the Apple Watch's "Taptic Engine", according to the Wall Street Journal. The problem is causing shipping delays for many customers, so if you haven't gotten yours, now you know why.
The taptic engine is a linear actuator that lets the Watch give you a little taps on the wrist. It's haptic feedback that's subtler than the buzzes you get from vibration motors on other smartwatches. It sounds like a neat idea! Unfortunately, the WSJ says that one of the two big suppliers is making parts that don't work properly. Apple has reportedly moved almost all of its production to the Japanese supplier that does work.
The report makes sense given that the Apple Watch appears to be in short supply. Customers still face long lead times, and stores still don't have inventory to sell. It's worth noting that the story. based on unnamed sources but you can usually trust the WSJ's supply chain contacts.
Just goes to show: Never buy the first version of Apple anything.