This is because of a hardware parts substitution that was made in the factory by accident: specifically, where we’d specified jacks with integrated magnetics in the BOM and schematics, the factory soldered in non-magnetic jacks. No magnetics means no network connection.
It’s cool to see Pi posting about the process of making the Pis.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.