What channels do you see when smart connect is disabled on 5Ghz?
36, 40, 44, 48, 149, 153, 157, 161, 165
this stuff goes over my head quick but i think i found answers to the other post too
i have a lenovo t560 laptop with intel dual band wireless-ac 8260. windows 10 says i'm connnected to 5ghz on channel 157. link speed is 866/866
speed test i just ran with speedtest.net win10 app - it peaked at just over 300Mbps before slowing down and finishing at 242Mbps.
Its more or less like this for my Google Pixel 2 XL and Samsung Galaxy Tab S5e. I tested an iPhone SE (the new one) and that one can do over 500Mbps so i'm not sure whats going on