So the solution is to download the firmware? I bought the TL-WDR4300 as well because the promoter said it supports Unifi (even had the 'Supports Unifi' sticker on the box), but when I finished setting up the router, the wireless network can be detected and connected to, but there is no internet connection.

I spent hours trying to do just anything but then I gave up and switched back to the old router and now I am here, finding solutions.