One possibility is that the Ethernet cables are crossover ones, which many devices won't care about but some devices do.
That is possible, but the switch at the other end is a Cisco one that senses crossover cables and adjusts as needed so would be surprised is that's an issue, but I will get out my cable tester.
I wasn't having a very good day yesterday when moving my router from behind the TV and relocating it in the utility room. It started off well as the router is now in a more central location within the house and as a result, there's WiFi signal all around the house, which is great. But for some reason I'd first unplugged the existing cat5e cables from the wall-socket near the TV, then later on plugged them back in after connecting them to the PVR and TV but managed to plug in the first cable upside-down, thus destroying the spring connectors inside the RJ45 module and breaking the retention clip on the cable boot, so the cable is now useless. Cue ordering a replacement RJ45 module and some tricky replacement of the broken module, unless the damaged module is repairable?