@Kevin_Z  My internet service provider is RCS & RDS Romania and the bandwith I paid was 1200 Mbps total.

Yes, other devices work for ex. My phone, my family member's devices, and my OS is Windows 10.

I ran 3 speedtest.net tests, here are the results:

Test 1: Ping 2, Download 203.32 Mbps, Upload 154.46 Mbps

Test 2: Ping 2, Download 286.23 Mbps, Upload 155.59 Mbps

Test 3: Ping 2, Download 297.39 Mbps, Upload 157.21 Mbps

I did a total too (adding them togheter): Ping 2, Download 262.31 Mbps, Upload 155.75 Mbps

Also, I had a Router that was supposed to be slower but it worked better, just telling if this info may help.

I have also tryed before to plug out the internet cable and putting it back, but it didn't seem to work.

Kevin_Z wrote

@PURPL3 

 

Who is your internet service provider and what is the bandwidth you paid? 

 

From your description, do other devices work well except yours? If so, what is the model and OS version of your device? 

 

With it connected to the Archer C1200, what is the speed you can get? You can go to speedtest.net to run it for 3 times. 

 

Besides, you can forget the network and reconnect to the TP-Link wifi to give it a go. 

 

Or try to change the wireless settings, like wireless channel, channel width. 

 

Best regards.