@Kevin_Z Hi Kevin, thanks for your reply. I've solved this issue by re-installing the Windows 10 OS. It might be one of the Windows 10 updates which are not capable with the T9E Driver.

Hi there, I bought a TP-Link Adapter Archer T9E on December 2018. Recently, the adapter cannot connect to the 5GHz channel, even it connects to the 5GHz channel, the connection is unstable. There is...