M8s+ ethernet not working with some cisco switches

[koutroul]

Hello I have some M8S+ boxes and I installed them on some cisco 3750 switches. Ethernet green lights are flickering both on swicthes and tv boxes but when I enter menu at Ethernet shows "Not Connected". I tried connecting my laptop and other computers to the cisco 3750 and they are working perfectly. When I connect them to the cisco SF300-24P swicthes so some reason ethernet shows "Connected".

Why with all the WS-C3750-48TS-S swicthes ethernet is not showing connected even if lights are flickering both on swicthes and TV boxes and despite the fact that laptops are working fine on the swicthes.

Thanks