Mark:
I’ll defer to Brad officially.
The ping tests high rate of failure is concerning. That should not happen.
Does the XEP have a static or DHCP address? Does the XEP and your wife’s computer by chance have the same IP address? If so, then that could possible cause similar symptom. Not likely but it can. In this case the two network adapters are both trying to connect into the network which causes problems.
You could set up and connect the XEP into a standalone network switch and then use another computer (that is also temporarily connected to this switch) to ping the XEP interface. If the ping response drops packets like before then it is possible that the XEP needs further investigation. If everything works then you have further insights that maybe the XEP does work fine. It could be a switch port or cable as well. Take that into consideration as part of your troubleshooting.