Tried a few things but I really don’t understand what’s the problem. Here’s an even simpler blueprint which just removes foliage instances around the player. It works fine in the editor but not in standalone…
edit : Oh I just found a similar thread that was suggested to me that I didn’t found during my search : Remove instance not working with packaged project - Asset Creation - Unreal Engine Forums
Apparently you now have to use “Use dynamic Instance Buffer” on the foliage static mesh component that the foliage uses. So make a new blueprint from the original one and turn this on and apply it to your foliage and you should be able to remove instances during runtime.