also, the cable test using intel adapter utility doesn't give any error.

@Clive_A yes it is the switch SG3428X-M2.It is a brand new cable installation.

Thanks @Clive_A yes, on the router I have a SFP+ to RJ45 adapter. On the computer side I have Intel Ethernet 10 2P X-550-t adapter which has two 10G ethernet ports. I am using ethernet cat 7 cables...

@Clive_A Thanks for your reply. The router has 4 10G SFP modules to which I am connecting and not to the 2.5G ones.

Hello, My PC having two Intel 10G 2P X-550-t adapter connects to TL-SG3428X-M2 (this model doesn't appear in the list above but I find TL-SG3428XPP-M2, I hope they are same) through ethernet cat 7...