I've searched the forums but for some reason can't find the answer here. I have grouptype set to points, Keep in Bounding regions enabled and set to Bounding Object, and the bounding object is a set of boxes. This is weird because I have another group node a few nodes up and that one is working perfectly fine with the same setup.

Try recreating the Group node. Would also help if you post your scene.

in case someone face the same issue, try fusing the points before copy to points!