The test is being done over WiFi as that’s what my computer is run on currently. Unfortunately, I do not have a cable long enough to go wired with Ethernet. Though the PC is only approx 15-20ft away from the router. I should be getting the advertised speeds even over WiFi though, sure there might be some loss due to hardware but when paying for 600mbps getting 200mbps isn’t acceptable.
As far as other devices, I thought the same thing. So I moved everything other than my PC over to the Guest 5ghz network and only connected my PC to the main 5ghz network. That bumped the speeds maybe 10mbps, so really not much gain.