I have set up the Archer AX300 router with the same SSID for both the 2.4GHz and 5GHz wireless bands.

Out of 12 clients (including 2 printers) 9 connect over the 5GHz with no issues if the network adapters have the "Preferred Band" or "Band" properties set to "Auto".

On 3 devices (1 older MS Surface Table, 1 older MS Surface Pro tablet, 1 new MS Surface Pro tablet), if the "Preferred Band"/"Band" property is set to "Auto" they only connect to the 2.4GHz network when they are 30-40 feet from the router, but randomly connect to either 2.4GHz or 5GHz when they are in rooms that are further away from the router.

When they connect via the 2.4GHz band, the download speed is never over 4Gb, where it is generally at 50Gb when they connect via the 5GHz band.

The wireless controller in these devices is the Marell AVASTAR Wireless-AC Network Controller.

Any help figuring this issue out is appreciated.

Thanks,

Eric