In the latest Steam Client Beta for Desktop released December 13th, Valve has now fixed the New Big Picture Mode not working for those with NVIDIA GPUs along with plenty of other fixes.
Previously, it would try to launch and get stuck and not actually display anything but you would hear the intro video playing. Now it seems to launch just fine, although it feels a little sluggish overall with all the animations and fading effects that it does. Still, nice to have it actually work now though.
They also still haven't yet fixed the issue of it showing what's behind the window when you bring up the Steam menu
Here's all the changes noted by Valve:
- Fixed several issues related to popup dialogs being sized incorrectly
- Fixed issue where game hover UI would sometimes get stuck in the upper left corner of the UI
- Fixed sizing of app details DLC hover
- Fixed regression where clicking on DLC & "view all" in the dlc rollup not navigate to the store
- Fixed "Move" and "Uninstall" not working in content management UI.
New Big Picture Mode
- Fixed issue where a browser opened by a game was sticking around after closing the overlay
- Fixed launch options dialog not closing when cancelling game launch
- Various fixes to make the UI scale better in higher resolutions
- Fixed issue where the virtual keyboard would continuously be made visible after exiting a game
- Added option to start in windowed mode under Settings => Display => Big Picture Mode => Windowed
- Added direct navigation to controller inputs and modes from the preview screen
- Fixed the XBox layout preview page layout having some incorrect items and missing others
- Added a specific XBox Elite layout preview page
- Added a specific Switch Pro layout preview page