I moved to a new room last year and compared the long BJC Ethernet run to a TP-Link Wi-Fi extender with a short piece of decent Ethernet to my Innuos. The long run added some noise/glare, the Wi-Fi extender was better. I then added a Smoothlan to that setup and things settled down even more.
I have the same WW USB cable, that is a good one. Power conditioning is probably an issue as others have stated, but more expensive to fix. One thing at a time.