My Macbook Pro running Big Sur doesn’t seem to recognize that my Hip Dac is plugged in. The audio plays through the Macbook’s speakers with the Hip Dac plugged in and Grado headphones plugged into the Hip Dac. Works fine plugged into my Galaxy S20 Ultra.
In the above screen shot I’m showing the System Preferences/Sound dialogue box just below the right side of my menu bar. Because I have Show volume in menu bar selected, I have a speaker icon on my menu bar. When I want to switch my audio output to a particular device, I click on the speaker icon, then click on the output device I want to use.