C6300 AC1750 slow wireless internet speed

[sandynet]

Xfinity provides 200mbps for me but while connecting to the router I am getting 20 Mbps using any 2.4 ghz or 5 ghz. But connecting using wire I am getting 200 Mbps. 

Tried changing the channels and MTU size but nothing helped.  Can someone please provide any tips?

Firmware: - 2.01.22

OS:- Windows 10

Thanks.

[DarrenM]

Have you tried to connect with 1 wireless device and nothing else connected to the wireless and see what speeds you are getting?

DarrenM