I have an ethernet cable running from the Hub 4 to a switch in the loft that then delivers ethernet to all upstairs bedrooms. The speed on all of these devices dropped overnight to under 100Mb for no reason. I swapped out the switch but that made no difference. Downstairs, all other directly ethernet connected devices were still getting 850Mb
I disconnected the cable going to the switch and plugged that directly into my laptop - 87Mb - thereby suggesting the port or cable. I swapped cables round on the Hub and full 850Mb was restored to ALL devices.
I still can't work out why the hub was limiting one port until cables were swapped round...
