The day I received it, at home I did a couple hours of breakin and function tests and I had no problems with 1. USB: Laptop USB-A out to Bifrost USB-B input; nor 2. Optical: Chromecast Audio Dongle output to Bifrost optical input.Have you observe it working differently with a different source? A computer or iOS device, maybe?
Now that the BF2 is at my workplace, I can only troubleshoot on business days but that is a good idea: I'll take a laptop and tablet in and test those on USB as well as a process of elimination to see if its my phone.