Only 2 channels functioning on THX Spatial Audio

I have a Nari Ultimate, and I've had a recurring issue with only 2 of the 7 channels on surround sound functioning when using the THX Spatial Audio. It was working for about 2 weeks straight before I started having issues. There were no hardware/software changes on my PC. I have run a repair install on the Synapse software, clean uninstall/reinstall, reinstalled drivers, and extensively played around with the settings. It started working at one point after the 3rd or 4th time of doing the repair install, which lasted all of 2 days, and now I'm back to it not working again. It's the same 2 channels that function. I can tell exactly which channels are no longer functioning by doing the calibration in Synapse under the "Mixer" tab. I've tried using a guest profile in Synapse, and same issue. I tested on a second PC, and it functioned perfectly there, so the issue only exists on my primary PC. I would appreciate any assistance on resolving this.