Could you please explain how this could possibly be a chipset problem? The chipset sends and receives packets without problem. It's a pretty rock solid chipset

Could you please explain how this could possibly be a chipset problem? The chipset sends and receives packets without problem. It's a pretty rock solid chipset in my testing. This sounds like an "Apple didn't implement AirPlay support in the driver" problem, which sounds crazy, because it is kind of crazy. AirPlay should just be packets on the network like anything else. You also seem to be digging pretty hard to try and justify your original position, which was very extreme. No, Apple computers are not stuck at 100Mbps. This would be a very big deal, as tons of creative workflows rely on having multi-gigabit network connections. The outcry would be enormous. I had never tried to use AirPlay 2 from my laptop over ethernet (I can probably count on one hand the number of times that I've used AirPlay from my laptop at all), but I tested, and it is true that the Music app won't connect to AirPlay devices over this Ethernet adapter (but it will over the 8153). I also have no problem redirecting the system sound to an AirPlay device, even over this Ethernet adapter, as that comment says.