Moode USB Output

[pyhfsg]

I have a Raspberry Pi 4 and a pair of Klipsch R-51PM Active Speakers (running Moode 6.7.1). Since the speakers have a built-in DAC and a 100% digital amp, I want to keep the signal digital throughout the entire pipeline -- so I figured I'd use the USB output on the Pi. Moode recognizes the speakers, but no audio will come out of them. One time (in ~10 boot-ups) they did actually work with the settings below:

I2S = None
MPD = Set to my speakers (Moode sees them no problem)
Volume Control = Hardware
Volume Control = Disabled / 0db
DSD over PM = No
UAC2 Fix = No
Tried USB 2.0 and 3.0 ports (the one time it worked was on USB 3.0)

Moode seems to think it's playing to the speakers; there are no errors or warnings. I tried hooking up another powered USB speaker (SoundBlaster Roar 2 with built-in DAC and Amp) and it works perfectly (using the settings above). The Klipsch work fine with my windows 10 computer. I'm stumped.

I have HDMI turned off and am accessing Moode through the Pi 7" touchscreen (which by the way is absolutely amazing with the Moode Theme "PUre Black" which works perfectly on a screen that size).

Also, would there be any audio quality improvement if I purchased a HAT with Toslink Audio as opposed to the native R Pi 4 USB audio?

Any advice for a newbie?