(18 %) high packet loss identified by my xboxone console

This unfortunately is actually a known  issue with the Xbox One connecting via a D3 modem.  Other devices in your home are likely not seeing this packet loss.  Last I heard all relevant details were sent to Microsoft as technical feedback however I'm not aware of any developments on the issue.  I believe some have suggested that you could experiment with QoS settings in your router to mitigate the issue until a fix is deployed.