So far, their explanation is that the network adapter is “too advanced” for the router, and because this information comes from the router and not the adapter, Network Utility cannot display it. I’ve contacted Apple support on the Network Utility problem.
But the option-click on the network icon is by far the best. I did eventually stumble upon the System Report method. I’ve confirmed this with other 2018 Macs in BestBuy and the Apple store. It shows 54 Mbps, no matter what network you’re connected to. My first thought was to look in Network Utility, but on the 2018 computers this doesn’t work. As you point out, just clicking the network icon in the menu bar doesn’t provide that information. I just bought a 2018 MacBook Pro 15 and I’ve been trying to find my WiFi connection speed.
