Pioneer DDJ-S1 + Serato Audio Output Issues

Hi,

My Pioneer DDJ-S1 is not outputting any audio through the master (aka my laptop speakers or my external speakers). It is only outputting audio through my cue headphones when the cue button is pressed. I can't figure out whether this is a hardware or software issue. I'm on OS X Mojave 14.1

Things I've done to date:
- Updated the firmware and software
- Set "Built In Output" and "Built In Output" as the selected input and output for my Mac in Audio MIDI Settings
- Created a new "Untitled" MIDI configuration with the Pioneer DDJ-S1 and the IAC driver

It seems like these issues started when I upgraded to Mac OS X Mojave. Please help! I'd love to have more than just my headphones outputting audio!