@idnurHidayat 

Hi,

Maybe if you could provide the log output from freeradius that might give TP-Link some clues.

Anyway, I have never dealt with WPA-Enterprise previously, but today I thought I might give it a try as well on my Archer C64, which is based on the same router chip and is also at firmware version 1.12.1 Build 221212.
I followed the steps in the article you mentioned one by one, but my Windows PC was also unable to connect afterwards.
The freeradius log showed the following errors while the Windows PC was trying to establish a connection.

Okay, I don't know the reason for it, but in my case the EAP configuration file of freeradius "./mods-enabled/eap" contained just some (incorrect) dummy links to the key and certificate files.

So, in addition to what is shown in Step 3 of this guide https://www.tp-link.com/at/support/faq/3456/ there were three more lines that needed to be modified to read:
---------------------------------------------
private_key_file = server.pem
certificate_file = server.pem
ca_file = ca.pem
---------------------------------------------
Afterwards my Windows PC successfully connected to my Archer C64 using WPA2-Enterprise with authentication by certificate.

Given that id-nurHidayat had WPA-Enterprise already working with another router the above couldn't have been the cause of the problem and there must be some other reason why it doesn't work with the Archer C80.