good point, double checked, the port has Gb Ethernet set up and attaching the Mac on that port gives full speed ... Still guess ists an issue of frequency overlap with the different AP's. On the...

Having a 500 MBit symetric WAN Access on my ER605 V2 which works full speed on all ethernet ports. Also I don't have any Rate Limit set up with the WLAN or even any Profile. Still the maximum speed...