If the network switch and the Ethernet port are not talking at the same speed it can cause this kind of issue. Can you ping between the server and the workstation across the network switch? Is the network switch getting any packet errors?
You mention that the untouched switch is working and PC’s on that switch can see the server. It’s possible that the second switch may not have the ports configured correctly if you have implemented vlans or ports aren’t configured properly. Also, it’s possible some cables didn’t get moved correctly.