@MysticMac Hey there, you should find the 1.13.5 firmware here if you're using the US variant of Archer C6. Just upgrade it to 1.13.6 once you're done with the first step. This is the link

@terziyski I've already tried that. Seems to be exactly the same no matter what cable I use. I've tried a basic Cat 6, Cat6A, the Cat5E that came with the router, I've even tried changing the ONU....

An update on the issue. The service center called me about the router a while ago. They asked me to take it back, they couldn't find any issue with it. They said it was working just fine. And...

Hi @Marvin_S, thanks for the suggestion but I've already sent it to the service center yesterday. I'll wait for them and post an update here later.

@terziyski I see, maybe the tp-link employees here can tell me something about it? I was a bit busy today, so I couldn't take it to the service. I'll do it tomorrow, and it'll probably take them...

@terziyski Could you tell me why is that? Was there any problem with the firmware? Or in my method of installation? Or is it just something else? And anyways, about the version of the firmware. I had...