How do you have everything connected? With ethernet cables in every product? Just one product with an ethernet cable, or is everything connected wireless with your router?

I have had a similar issue, turned out, I had every component connected with an ethernet cable, and the system got messed up. I removed all ethernet cables except the Arc and turned on the WiFi on all devices. Since then no problems anymore

My amp is connected via Ethernet cable however that’s only used to connect turntable to and isn’t part of the room network. I’ll try to remove that cable and see if it makes a difference. Thanks. 

A turntable connected by ethernet? Are you sure?