Yes, I noticed the problem. This happened because your surface is narrow. I tested it myself and this problem happened to me too. This problem occurs when you use the scale. It is better to use Unreal Geometry “BSP” to model or use a high poly for narrow place
Thank you very much! I work on a datasmith model imported from Revit and I can’t edit them.
Strange that sometimes it doesn’t recognise foliage or can’t delete it, maybe it has some compatibility problem with this type of mesh.