How about wired speed of the Archer C9? if wired speed is normal, changing wifi channel and channel width usually improves the wireless speed, if not, maybe you can check the firmware update

I have upgraded the firmware to the latest version, this had no effect on wireless speeds. By changing the channel on the 5 Ghz band I am now getting 160 mbps, however I did not have the same luck with 2.4 Ghz. Tried every channel and the most I can get is 52 mbps. This appears to be a bandwidth issue and for now I am satisfied with the results. Thank you for your suggestions.

I have the same issue with my Archer C9, the range of 5Ghz is not good at all.
So what channel did you changed it to so you get best wifi-speed for 5Ghz ?

Svsportsman wrote

I have upgraded the firmware to the latest version, this had no effect on wireless speeds. By changing the channel on the 5 Ghz band I am now getting 160 mbps, however I did not have the same luck with 2.4 Ghz. Tried every channel and the most I can get is 52 mbps. This appears to be a bandwidth issue and for now I am satisfied with the results. Thank you for your suggestions.

Channel 36, bandwidth auto

Try
Power down all of the WIFI devices
Power off/on the router
Check that no WIFI devices connected.
Power on a WIFI device that can check the speed
Connect it to the 5 Ghz and check the speed
Connect it to the 2.4 Ghz and check the speed
If all is well, power up each of the other WIFI devices checking the speed after each

I suspect you may have an older device that may cause it to run slower such as an old printer that runs in "G" mode.

Hope this helps.

I also got the Wifi speed back to normal by changing the channel. I can now video conference again and watch Youtube videos in HD.

But is not the idea with auto channel that it selects the best one?