I have been trying to figure out what that problem is for this and I would REALLY appreciate the help from anyone.
This is the area that I wanted to boolean.



Steps I did was
I select the cube and use the boolean modifier using the difference operation.
I select the object I wanted to use (in pictures).
I apply the difference modifier and some of the objects were able to work but the other vertices were stuck in the plane for some reason.
If anyone can help with my terrible way of explaining it would be nice and greatly appreciated. (I hope it's not me being stupid)
