@goex54 - Interesting. Is it possible you have a digital ground loop? Do you have a Cable TV coaxial cable coming into your system as well?
Coaxial digital cable can of course create a ground loop IF the DAC isn’t galvanically isolated, which sadly is not 100% of the time.
Another source for digital ground loops is from the streamer, especially PC’s. If you are using a laptop unplug it from the power supply. If this is your problem a USB isolator is in order for you. Again, IMHO, all DAC’s should have galvanically isolated USB and coax but they do not always have this.
Meaning, there should be no metal to metal pure pathway in. An isolator, usually a transformer, is used to prevent DC current and ground loops from forming.
In the digital domain weird effects like clicking, as well as not quite so audible effects like severe jitter, and even very audible hum are possible symptoms.