I’m having the same (or possibly just a similar) issue on my project. For me, whenever I load a level with a landscape all the landscape shaders need to be recompiled. I don’t even need to close the editor, just go to a different level and back again. I was hoping the Boy and His Kite sample would have the same but no luck. Working on stripping out most of the content from my project so I can post it with a bug report on the AnswerHub.