Retrieving information from texture not working in shader graph

I'm trying to store information in a texture and retrieve it in a shader graph custom function, but it's not working no matter what I try. I'm trying to sample the exact center of the pixel (i, 0), of a texture that has TextureCount x TextureCount dimensions, but the numbers I'm getting are very off. Here is the line that causes the issue:

 float StartHeight = SAMPLE_TEXTURE2D_ARRAY(StartHeights, samplerState, float2((0.5 + i) / TextureCount, 0.5 / TextureCount), 0).r;

Any help would be very appreciated, I've been trying to fix this issue for about 5 hours now and am at the point that I can't see anything other than a Unity bug as the issue.