USB A to TOSLINK Optical Audio Adapter, Unidirectional USB Type A to SPDIF Digital Converter, S/PDIF Transmitter for Computer Laptop PC PS5/4 ONLY-Includes Fiber 3.3FT Optic Cable

huh yeah it's an odd problem... from what I've read it may be that the Bose soundbar is pickier about how clean the signal is vs. the Yamaha, and your motherboard might be introducing some noise to the signal. You mentioned running in exclusive mode, so did you also try with exclusive mode disabled (both "allow applications to take exclusive control of this device" and "give exclusive mode applications priority" unchecked)? In case some rogue app is taking control. Other than that, all I can think of is to try a usb to optical adapter like this https://www.amazon.com/TOSLINK-Unidirectional-Converter-Transmitter-Computer/dp/B0GFNSTQX6/ref=sr_1_4