I'm helping someone identify the different Ethernet ports around their new home. The patch panel doesn't have any labels. At the moment, the ONT is connected to one of the ports. They have 5 outlets around the home however they are not using a switch.

The issue is that one of the ports ins't working. I tested this with a Fluke Networks tester and it shows up as a miswire. I'm thinking the fault is on the back of the keystone jack, maybe the wiring isn't quite right?

Would this have been tested by the sparky when the house was built? (2012) or maybe the ethernet cable was yanked out and the port is now damaged?