Vulkan Fullscreen Sound Problem

When running Retroarch in fullscreen with the Vulkan video driver, sound is not being pushed to the desired device. I have two sound outputs, a tv and a pair of speakers built into the computer. When running Vulkan in windowed mode sound is played like expected from the TV, when running it in exclusive full screen or borderless windowed fullscreen sound is always outputted to the pc speakers.

This happens regardless of what audio driver, audio device, or monitor is set in retroarch. The other graphics apis work as expected and output to the tv regardless of video mode. the TV is set to the default audio device in Windows itself. Disabling the pc speakers doesn't resolve this, Retroarch still attempts to push the audio output to them without any sound coming out. In the volume mixer retroarch.exe is shown to be using the tv output, but the emulation instance that is running is shown to be running using the pc speakers for audio.

This problem only started to occur after updating to Windows 10 21H1 or updating to the latest Intel HD Drivers (30.0.100.9684). I am not 100% sure which might be the cause because I updated them at the same time and only recently got around to trying Retroarch again recently. I unfortunately can't downgrade Windows 10 to the previous version as I deleted the old update to make room on my ssd. Previous to these updates Vulkan worked as expected on 1.9.6 stable. After these updates I updated to 1.9.7 stable and tried it and had the issue, assuming it was a bug introduced in the new version I downgraded back to a clean copy of 1.9.6 but the issue still occured where previously it did not.

I am using a mini pc (the HP 800 Mini G2) with 8 gigs of ram and a i5 6600 with Intel HD 530 graphics. the computer does not have a dedicated HDMI slot so I am using a Displayport ++ to HDMI cable. The TV is Samsung. Retroarch is being run on a Samsung Evo SSD.

retroarch__2021_07_28__15_29_47.log

I have included a log file of what it looks like when running under the above described conditions.

Thank you in advance for your time looking into this matter.

Start by reproducing the issue with Vulkan in exclusive and borderless fullscreen, comparing the attached retroarch__2021_07_28__15_29_47.log with windowed mode and other graphics APIs. Trace where the selected audio device is chosen for the emulation instance; done when fullscreen Vulkan uses the configured TV output without breaking other video modes.