Center Aspect Ratio not working as expected

Since the change to DX12, the game has not been following the Center Aspect Ratio setting set in the GPU settings.

I play with a resolution that is smaller than my monitor's native resolution. With the center aspect ratio setting on, the game is supposed to run at that resolution with black bars around it. Currently, the resolution just gets stretched to entire monitor.

On a March 2025 patch, there was a launch argument that was added that was supposed to fix this but it doesn't seem to be working:

Added a launch argument +mat_no_stretching 1: prevents all resolution stretching and will always letterbox or pillarbox your monitor to the game's resolution. Players should be aware that certain aspect ratios with this setting can break UI elements in the game, but this functionality is still useful for some players to replicate their DX11 setup with custom resolutions.