Router TP Link Archer C80 switching between 100mbps and 1gbps
I have this problem which is driving me crazy, my internet speeds are switching on my brand new TP Link Archer C80:
At first the tests are limited to 100mbps but when I switch between the ports something weird happens:
Speedtest #1 LAN port 1: 91mbps down/76mbps up
Speedtest #2 LAN port 2: 247mbps down/165mbps up
Speedtest #3 LAN port 1: 254mbps down/171mbps up
And then it seems like the speed goes back up to its normal but only for some hours, then it goes back to being limited to 100mbps
My equipments:
OTN: Huawei Echolife EG8145V5
Router: TP-Link Archer C80 (Internet Port Negotiation Speed Setting = Auto Negotiation)
Cables: Furukawa CAT6 e Furukawa cat5e
Computer 1 (Desktop):
Ethernet adapter: Realtek® 8111F-VL GbE LAN chip (10/100/1000 Mbit) (Motherboard Gigabyte B85M-D3PH)
Mode speed&duplex set on Windows 10: Auto Negotiation
Operating System: Windows 10 64bit
The exact same behavior occurs on my other machine (Dell Latitude E7440):
Ethernet adapter: Intel Corporation Ethernet Connection I218-LM (rev 04)
Mode speed&duplex set on Windows 10: Auto Negotiation
Operating System: Debian Buster 64bit/Windows 10 64bit
I don't know what to do anymore, should I return the router?