OP,
I'm pretty sure that @sns must have addressed this somewhere.
There are two approaches. Fix the network or get a better streamer. "Fixing the network" involves becoming and IT person and upgrading / quieting the router, and lines for the whole house. Typically audiophile router, special power supplies, etherregen... stuff like that.
Or, just get a better streamer. I would recommend an Aurender N200 or better. I own two Aurender and internal files and streaming sounds the same and simply stunning. My main system runs off a wall wart wifi extender and my $45K vinyl rig = CD = stored files = streaming... audiophile level sound quality.
I'd recommend a high end streamer... just a whole lot easier for those of us who do not want to fiddle with the network. I was in IT most of my career... I'm retired... I want to stay that way.