Only a 100Mbps connection is available, not gigabit speed.
Only a 100Mbps connection is available, not gigabit speed.
It turned out to be a poor CAT5E connection, but CAT6 resolved the problem.
It's possible or there could be an issue with the NIC socket. Experimenting by applying pressure at the RJ45 jack often reveals the problem. If the cable was defective, it might be due to improper termination of all four twisted pairs. I've observed this when a single pair is faulty, causing the link to drop from 1Gbps to 100Mbit.
I’m not really concerned since simply installing a brand new CAT6 cable resolved the issue, and I no longer need to be worried about it.