Hello everyone, 

For anyone who met similar issue that Archer T6E can't connect to the network,  please refer to the following information: 

1. If the adapter has been working fine before, remove the old Wi-Fi profile and reconnect to Wi-Fi network: 

How to connect to wireless networks and remove its profile on windows 10?

note: verify Wi-Fi password and confirm the password could be accepted on a different device like your mobile phone 

2. Please try to manually install Archer T6E driver:

https://static.tp-link.com/2019/201911/20191129/T6E Driver_BCM_4352_QAM256_win10_beta.zip

note: if the above driver does not work well, please try the following one: 

https://static.tp-link.com/2019/201911/20191129/Archer T6E T9E_ASUS driver_7.35.351.0.zip

How to manually install the driver: https://www.tp-link.com/support/faq/920/

（Optional） try T6E BCM4352 chipset driver 7.35.267 on Lenovo website   ( Shared by @hadus in post T6E drivers (working))
(google: BCM4352. Find the link to lenovo support, should be around the 4th in the list. 

3. For a test, create a mobile hotspot Wi-Fi with simple Wi-Fi password like 12345678 or unsecured  Guest WiFi network  and see if T6E could not that ?

If the above  failed to solve the problem, please create a new thread here or  send an email  support@tp-link.com with subject ' [Forum ID 222782 ] Archer T6E + Description ' with case details below: 

1. Did the problem happen just after the windows10 update? 

How long has T6E working fine before on the computer? 

2. Please check the system info and driver info about your computer and share the photo 

https://www.tp-link.com/support/faq/2722/

3. Is there any error message when it failed to connect the network?

Did you have the same issue on both 2.4ghz and 5ghz Wi-Fi band?

4.  Model number of wireless router

A photo of Wi-Fi settings of Wi-Fi Router

Thank you very much for your cooperation and support.