@Thommo17 I'd just like to let anyone else who searches for an answer to this problem that the TP-Link SFP+ modules fix the problem I bought an SM5110-SR to be plugged in the switch side of the fibre...

Hi everyone, I have a SG3428XMPP that has the same issue. I have 3 X520-DA2 cards. 1 in a Dell R730 another in my Windows 10 PC and 1 spare. All of them have "Intel E10GSFPSR SFP+ 1G/10G SR Optic...