Writing to render texture in for loop not working (metal)

I have written a compute shader that fills a 3D render texture with simplex noise. It works perfectly with on my Windows machine with DirectX, but when compiling on Mac with Metal it produces very strange results. I have narrowed the issue down to the for loop. It seems that writing to a render texture in a for loop doesn't work properly on Metal. Is this simply a limitation of Metal, or am I missing something?

octaves is set by a C# script and id is the dispatch thread id

 RWTexture3D<float> noiseValues;
 int octaves;

...

 for (int i = 0; i < octaves; i++)
         {
             noiseValues[id] += SimplexNoise(float3(id + chunkPos) / scale * frequency + offset) * amplitude;
             amplitude *= persistence;
             frequency *= lacunarity;
         }

I also tried replacing octaves with a literal, which still does not work:

 // Still broken
 for (int i = 0; i < 9; i++)
             {
                 noiseValues[id] += SimplexNoise(float3(id + chunkPos) / scale * frequency + offset) * amplitude;
                 amplitude *= persistence;
                 frequency *= lacunarity;
             }

However, adding [unroll] above the second loop does work, which makes sense as it is essentially the same as copy and pasting the code 9 times. The thing is, for my uses I need it to loop based on a number set from a C# script, so I can't unroll it.

Some other things I have tried include using a ByteAdressBuffer for the octaves variable and adding [loop] and [allow_uav_condition].

Below are screenshots of the 3D render texture in the inspector:

On windows, working

On Mac using Metal

(image upload gives error for some reason so had to upload elsewhere)