Had the Archer C80 for a while now and worked very well. We have a 80Mbps fibre connection which would give us around 60-70Mbps over wireless until recently.

This week all devices connected, whether 2.4 or 5Ghz, and also whether wireless OR via Ethernet test at 35Mbps. It's as if there's a cap on it. Every single device, every type of connection (wired or wireless, 2.4 or 5) tests at 35Mbps.

2 x Ipads, 3 mobiles phones a Chromecast and a laptop on Wifi and a smart TV and PC on Ethernet all testing at exactly 35Mbps??

Set up in Access Point Mode

Can anyone make any suggestions? 

So far I've updated the firmware, replaced Ethernet cables in the whole setup and rebooted