Windows 10 1709 Wifi in 5ghz download speed absolutely slow like 2Mbits/s

[elvior2]

I don't understand why my windows 10 my wifi adapter in 5ghz band is going really really slowly speed in download speed 2Mbits/s.

Connection link says 780Mbits/s and upload speed is fine like 300Mbits/s. It's only download.
Never have this problem.

In 2.4ghz band does not have this problem but 5ghz has been working fine all the time.

I'm using Windows 10 latest build and adapter is Linksys WUSB6400M. I've tried reinstalling drivers, use windows defaults, linksys drivers, realtek compatible for the chipset inside the adapter without success.

Other devices in home, Ipad, mobile phones and laptops works in 5ghz band without issues and proper speed.

 

[elvior2]

For anyone that is having a similar problem I discovered it's all related to drivers of USB Root Hub and USB Host Controller.

In devices in control panel I saw some generic drivers from Microsoft.

I search for drivers in my case AsMedia and found this page https://www.win-raid.com/t834f25-USB-Drivers-original-a...

Install new drivers and test again and saw no improvement at all in download speed.

Then tried a program call USB Device Tree Viewer were you can view actual connected devices for USB and their current speeds. My wifi adapter is compatible USB 3.0 and connection says is working in mode USB 3.0.

And here is the strange thing. When connected in 3.0 mode upload speed is correct 300Mbits/s but download is ridiculous low.

Change it to mode USB 2.0 and test again and saw speed is about 190Mbits for down and upload.

Really don't know why it's not working is USB 3.0 for download.