Xi6-A Ethernet connection

I cannot get the Ethernet port to connect at 1 G speed. It switches back to 100 Mb speed. I have done all the default checks like cables, routers, loose plugs etc. When I connect my laptop to the same router port It works fine at 1 G speed. I am wondering if the WiFi is interfering with the Ethernet connection? In the settings on the TV there is not an option to turn off the WiFi.