Halo 4's forge

I was recently building a map in forge today and I noticed that when you exit the game and go back in, some of the forge pieces will be out of place, so why does this happen? This was not the first time this a happen to me but I find it so annoying that sometimes I would already put it in my file share and the floor would be out of place :confused: What is wrong this forge and why is 343 not fixing it?