Metal 3 MTLIO Loading multiple textures w/single command buffer causes data corruption

Is there a limit to the number MTLIO load texture commands that can safely be executed in a single command buffer?

When I tried loading each face (6) of a cube texture using a single command buffer, some of the faces will have bad data. Basically...

let cmdBuf = ioCommandQueue.makeCommandBuffer()
for slice in 0...5 {
    cmdBuf.load(cubeTexture, 
                slice: slice,
                level: 0, 
                size: size,
                sourceBytesPerRow:bytesPerRow,
                sourceBytesPerImage: bytesPerImage,
                destinationOrigin: destOrigin,
                sourceHandle: fileHandles[slice], 
                sourceHandleOffset: 0)

}
cmdBuf.commit()
cmdBuf.waitUntilCompleted()
/* This passes, even though my texture is messed up...? */
assert(cmdBuf.status == .complete) 
// Also, no errors or warnings when XCode Diagnostics / Metal Validation is turned on.

If I use multiple command buffers (one load texture command each), everything is fine...

for slice in 0...5 {
    // IMPORTANT: Moved inside the LOOP
    let cmdBuf = ioCommandQueue.makeCommandBuffer()
    
    cmdBuf.load(cubeTexture, 
                slice: slice,
                level: 0, 
                size: size,
                sourceBytesPerRow:bytesPerRow,
                sourceBytesPerImage: bytesPerImage,
                destinationOrigin: destOrigin,
                sourceHandle: fileHandles[slice], 
                sourceHandleOffset: 0)

    // IMPORTANT: Moved inside the LOOP
    cmdBuf.commit()
    cmdBuf.waitUntilCompleted()
    assert(cmdBuf.status == .complete)
}

I'm assuming this a bug (opened FB10582329)... Or at the very least, some documentation or Metal Validation log would be helpful to understanding what's going wrong/workaround.

I've uploaded reduced reproduction (Single Swift file, command line application, XCode project) to this GitHub Repository: https://github.com/peterwmwong/x-mtlio-load-multiple-textures

Thanks.