Foliage Not Deleting

I’m just getting in UE4 and I’ve been designing a level, putting down grass, rocks, trees etc. and there is a single type of grass which isn’t getting deleted and I can’t figure out why. I can individually select the grass objects and delete them one by one, but the eraser brush isn’t working. I saw previous posts with similar problems possibly regarding world composition (which I’m using), but I’m certain that the grass is in the current level. Any help is appreciated.