Validation error in DX12 but not Vulkan

[radgeRayden]

I author shaders using a SPIR-V generator. My output runs without problem on Vulkan (Linux and Windows), but when I use some features (as of now I managed to get the issue when using Storage Buffer bindings in the shader), it will work only on Vulkan. I had a Windows user generate traces for me of a very simple project using such a shader, which I will include below.
wgpu-trace-vulkan.txt
wgpu-trace-dx12.txt

When forcing the DX12 backend the user gets the following error (edited to add backtrace):

thread '<unnamed>' panicked at 'Error in wgpuRenderPipelineGetBindGroupLayout: Error reflecting bind group 0: Validation Error

Caused by:
    Pipeline is invalid
', src\lib.rs:3064:9
stack backtrace:
   0: rust_begin_unwind
   1: core::panicking::panic_fmt
   2: wgpuRenderPipelineGetBindGroupLayout
   3: get-bind-group-layout
             at C:\msys64\home\vboxuser\bottle\src\gpu\RenderPipeline.sc:112:46
   4: main
             at C:\msys64\home\vboxuser\bottle\demos\gpu\buffers\init.sc:85:9
   5: run
             at C:\msys64\home\vboxuser\scopes\lib\scopes\FunctionChain.sc:71:21
   6: main
             at C:\msys64\home\vboxuser\bottle\demos\gpu\buffers\init.sc:125:9
   7: __tmainCRTStartup
             at C:\M\B\src\build-MINGW64\C:/M/B/src/mingw-w64/mingw-w64-crt/crt\crtexe.c:267:15
   8: mainCRTStartup
             at C:\M\B\src\build-MINGW64\C:/M/B/src/mingw-w64/mingw-w64-crt/crt\crtexe.c:188:9
   9: <unknown>
  10: <unknown>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
fatal runtime error: failed to initiate panic, error 5