Why does the FX Map's iterate node have its own random seed? How is it different than the node's random seed? Is there some way to create a new random seed per iteration?

I've created a shape splattering FX map that uses a single quadrant node with an iterator at the top, which iterates once for every shape drawn. This is the first FX Map I've tried to make that uses a single quadrant node. Each shape starts out on a grid layout (X*Y), which I calculated using the total and $number ($number / total and $number % total). Then each one is randomly offset. And this is where I'm running into trouble. For many node counts, I'm getting strange patterns in the result, as if the randomizer is repeating the same results every so many iterations. I'm almost certain the patterns are caused by the shape positions, because everything else is non-random. Here is an example of one, where you can clearly see line patterns going diagonally through the layout:

The image above was drawn with each shape randomly offset using a range between -0.5 to +0.5 on both X and Y axes. Here is the function used to randomize the shape offsets from their X/Y grid layout:

I've verified that the grid layout is correct without randomizing the positions. But as soon as I start adding random offsets, I keep getting these strange patterns. Does anyone know why, or how to resolve this? Is the FX-Map repeating the same random results in some way?

I've created a shape splattering FX map that uses a single quadrant node with an iterator at the top, which iterates once for every shape drawn. This is the first FX Map I've tried to make that uses a single quadrant node. Each shape starts out on a grid layout (X*Y), which I calculated using the total and $number ($number / total and $number % total). Then each one is randomly offset. And this is where I'm running into trouble. For many node counts, I'm getting strange patterns in the result, as if the randomizer is repeating the same results every so many iterations. I'm almost certain the patterns are caused by the shape positions, because everything else is non-random. Here is an example of one, where you can clearly see line patterns going diagonally through the layout:

The image above was drawn with each shape randomly offset using a range between -0.5 to +0.5 on both X and Y axes. Here is the function used to randomize the shape offsets from their X/Y grid layout:

I've verified that the grid layout is correct without randomizing the positions. But as soon as I start adding random offsets, I keep getting these strange patterns. Does anyone know why, or how to resolve this? Is the FX-Map repeating the same random results in some way?