As mentioned in #8404, this is a multi-GPU issue with my setup. Because I use the G1 (second) GPU by default and not the G0 (first) GPU, I need to set __NV_PRIME_RENDER_OFFLOAD_PROVIDER=NVIDIA-G1 %command% in the launch options.
It's set to my G1 GPU because my HDMI cable is plugged into that GPU when I boot up Ubuntu - if I plug it into the other GPU when I boot up my computer, then everything is loaded to my G0 GPU instead.
proton 10.0-2x1 2025-10proton 9.0-4x1 2025-10proton experimentalx1 2025-10
Compatibility Report
System Information
I confirm:
steam-2396980.log: https://gist.github.com/shermansiu/6cf3a745444dcc5402c18c1f40a7819dSymptoms
The overlay is transparent when first opening it up. Alt-Tabbing away and back causes the overlay to be visible, but black. Clicking on things seems to work, as the corresponding game sounds seem to play in response.
Reproduction
System Info: https://gist.github.com/shermansiu/da33f7ae327a7386d9cb1b8c7085651f
Steam Runtime Diagnostics: https://gist.github.com/shermansiu/35c1b72652efba8ecdd134062b0fb91d