Hello @jendrula1337 

Thank you for starting a new thread.

It's good to know you have tried chipset driver for Archer T6E listed in this thread and try to delete the Wi-Fi profile and reconnect to the 2.4Ghz Wi-Fi network. 

You could also adjust the Wireless security to WPA/WPA2-PSK and see if that makes any difference.

For a test, try to a Guest Wi-Fi network without password and see if T6E could connect to it? 

May I know did you recently update the Windows version? To better assist with  your case, we will also create a support email TKID220837581 please check your email inbox later. 

  Hello @jendrula1337 

Thank you for more test, if the adapter have trouble connect to Wi-Fi network every time you reboot the PC.

• Try having the "Allow the computer to turn off this device to save power" option disabled

Adapter Properties settings>  Power Management tab> Uncheck   "Allow the computer to turn off this device to save power" box

If still the same, I suspect it can be the adapter have some issue working with certain PC motherboard, you may reach retailer to check the warranty, its better to exchange to different model. If the retailer can not help, kindly reply to the support email TKID220837581and  our support will follow up your case  further.