I hope you're not taking my comments as being critical as that is not intended. But the more I look at your squares here is what I'm seeing - look at those two bottom squares forming the tip of the heart, your reds do not go all the way to the edge of the block where on all the others it does. You have white going to the edge of those two. Move a couple of the other blocks to that area and see if it makes a difference to you. That will happen to log cabin blocks if you add to one side twice before the other side. Each block needs to be uniform to the previous one when you're trying to create an overall design. One of the projects in my design group was to recreate a block pattern using only log cabin blocks. I made the carpenters wheel and had the very same problem your having here. OK, now I'll keep quiet!! Good Luck.