Geek Pulse DAC issues

Does anyone else have this problem with a Geek Pulse:

I have the Volume Setting set for “Knob Control” and Input Select set for “USB” (and my Pulse is connected to my iMac Roon Core by USB). However frequently there is no digital read out on the Pulse and instead it reads “Mute.” The volume is not mute, but it is lower (or occasionally higher) than I want it to be and turning the knob makes no difference; the volume will not change or adjust.

Turning the Pulse on and off does make the knob respond little better, but it still reads “Mute” and while the knob may make a small change, it is not responsive in the way it should be. Meanwhile it continues to read “Mute” so I can’t even tell what turning the knob achieves because there is still no digital readout.

Perhaps related? What do the different choices under Digital Mode mean? I see FRM, SSM, FTM and TCM. Changing the setting makes no difference that I can tell and the readout continues to say “Mute” no matter the choice. I have this setting on FRM but no longer remember why I chose that originally.

Anyone who has had any dealing with LH Labs (source of the Geek Pulse) knows that customer support is virtually non-existent. Some of us have been waiting years for the delivery of our Geek Source Music Server and still don’t know when – or if – it will ever arrive. (Our money was already paid through “crowd financing” on Indiegogo years ago.) So any help anyone can offer would be very welcome.