Unfortunatelly not sure. It was used on a 100 mbps connection for 1.5 years and now i moved to a new appartment with gigabit connection. So even if it's faulty, I doubt they'd replaced it after that...

I tried with another cable and it's the same. It's a Cat 5e cable, but it transmits the 1000 mbps fine when connected directly to the ISP router.

I have a device before the Archer AX1500. - Connecting directly to it via LAN gives me 1gbit speed. - Connecting it to the Archer and then connecting wirelessly to the Archer gives me 1 gbit....