
Not 100% sure it's the connector but I was able to attach the cables at 100/100 speed. Used Cat6 23AWG from Monoprice so a quality cable. The only other option is my router, but it's high-end and works with factory cables. Couldn't find the cause yet, just listed it as a possible problem with the sockets. I'll update when I find out. Edit: Confirmed. Upgrading to higher quality shielded connectors instantly fixed everything with instant 1Gb/s negotiation. I've tried many of these kits on Monoprice 23AWG Cat6 Solid Core and in some cases got stuck at 100Mbps or even 10Mbps. Rating downgraded to 1 star.