Issue with Wi-Fi 6 AX201 /cannot connect to this network / 5GHz

[Iv_El]

Hello 

I have new Lenovo Yoga C740 with Wi-Fi 6 AX201 160MHz and router Asus RT-AC51U.

When I try to connect to its 5GHz network I receive error "Cannot connect to this network". 

All my other devices connect to it with no problem and the laptop connects to the 2.4 GHz with no problem. The router is very close, and the range is not an issue. I have tried multiple configurations and made clean installations of both the intel and the lenovo driver. 

The only solution that works for now is to limit the bandwidth to 20Hz from the router config, and I would like to use it's full capacity, and not to limit all other connected devices ...

[Khun_Doug]

Iv_El,

In the properties for the AX201, have you changed the 5 GHz mode to AC?

And what security type are you using on the Asus router?

[Iv_El]

Hello, and thank you for your answer.

I have tried changing to AC and it connected to the limited 20MHz 5GHz network, like in AX (it makes roughly 20Mbps ookla test both ways), then I changed the option in the router to 20/40/80, the laptop connected again, and reached roughly 50Mbps ookla test then I restarted the computer and was not able to connect again multiple times, even trying to replicate the same procedure.

When I connect to the 2.4 GHz network I reach roughly 50Mbps.

I am using WPA2-Personal Authorization, but tried with WPA2-Auto-Personal and even without password - cannot connect to not limited 5GHz.

It's interesting that there is no "Power management" tab in the adapter options, and I cannot forbid windows to manage it power.

[Khun_Doug]

Iv_El,

There is no sense in setting your AX201 to AX mode as your router is only capable of 801.11ac. The best you will achieve is an AC link. Depending on the speed of your Internet service, you would be able to use an N or A connection and have little if any noticeable difference.

On the properties for the AX201 you see an entry for 801.11n/ac/ax Wireless Mode. I would recommend trying option 2 802.11n, or 3 802.11ac. The best choice for Channel Width for 5GHz is Auto.

Have you checked the firmware level on your RT-AC51U router? I see the latest release is dated Sept. 22, 2020.

Are there other 5GHz devices in your house that are able to connect and maintain a stable link?

[Iv_El]

Hello,

After "forgetting"  the connection and adding it again it connects in AC mode, but still only if it is limited to 20MHz in the router config. The speed that I reach is again roughly 20-30Mbps. It never connects to the 5GHz network if it set 20/40/80MHz in the router config. If I connect to the 2.4GHz network it goes to 50Mbps. 

I have 2 smartphones  and another lenovo laptop with Intel AC7265 adapter connected to the 5GHz network with no issues. 

When I run the speedtest on the other laptop I get roughly 40Mbps when the connection is limited to 20MHz from the router and 60Mbps when it is set to 20/40/80 Mhz.

The router has the latest firmware 3.0.0.4.380.8591 / 2020-09-22.

I will probably stick to the 2.4 GHz network for now and will look for another 5GHz router to test whether the issue will appear again.

[Khun_Doug]

Iv_El,

If you are looking at another router, depending on the Internet speed you currently have, and anticipate having in the next few years, should  be a help in determining if you want an AX capable router, or just an AC router. Since you already have an Asus unit, you might want to look at the Asus RT-AC88U. That unit supports AC and is a true MU-MIMO. If you anticipate a bump in Internet service to something with a high download speed, you would want to look at an AX capable router. Especially since mobile phones are adding AX capable network support.

[Iv_El · Accepted solution]

Just for information, after getting new router (TP Link AX50) the issue is resolved.  Obviously there is some conflict with the ASUS RT-AC51U router.

Of course I cannot accept any of the solutions above, since they did not help.