I have what you might call a "little server" in my home "basement." I changed my fiber for this one
patch cords and since them my mining has been restrict, I do not know if the change of the patch cord could be related.
To figure out if the cable is right, you need to know what GBIC's/what type of fiber transceiver you got.
Is it singlemode or multimode? Was the old cable yellow? You also gotta watch the nm. (850 nm / 1310 nm)
I'm guessing you got it right if you get a signal at all. Did you by any chance touch the tip of any of the fiber-tips with your hand? If yes, you could be experiencing packet loss.
Do you get packet loss if you ping 8.8.8.8 or 8.8.4.4?
I'm just throwing stuff out there, I don't really understand your question.