I've noticed that when you take a Send to Back or a Bring to Front block and have something in front or behind the item that has that code in it and press play, but delete the block, it stays in the front or back while you're working on the project, even if you restart the project again and again. It makes it impossible to find the item that was sent to the back if you don't know what made it like that and don't need the Bring to Front block to bring it because it already was in the beginning.
There are lots of people stubborn to not get out of the project and are determined to find the problem, but can't, including me, so it would be quite helpful to make it so if there's no more Send to Back/ Front blocks in the code, it will be sent to the layer it was originally.
Example of the problem:
Me removing the code.