I have a foreach loop which is working mostly the way I would like. My problem is that on a few of the iterations, I have some odd behavior.

When you set a foreach loop it previews one iteration which I assume is chosen at random. In my version this iteration is set to the default “name” and it will display 1 piece of a voronoi fracture I created upstream. So I can clearly see what is happening to this one particular piece inside my foreach loop. The problem is the piece that is displayed is not one of the ones behaving oddly so it's hard for me debug for the other pieces.

Is there a way for me to change which iteration it is displaying so that I can work on one of the ones that is behaving oddly?

Are you using a for-each subnetwork or a for-each loop in the same hierarchy?
If you are using the for-loop in the same hierarchy, the Block End node has a single pass option.

Another option might be to temporary delete everything but one instance(point, group, primitive, or whatever you are looping) before going in the loop.

single pass is exactly what I was looking for. thanks for the help!