Blocks disappearing when reloading

I'm from Brazil and I'm using the google translator, so I apologize for any problems that may appear.

I created a plant that looks if its surroundings have any blocks, if there is only air it adds a block where there was air. When I went to test it was working very well, but when I left the world and went back in, the blocks she had created around her disappeared, so she has to put everything back in. I need help!

PS: I found out that this is happening with the blocks as well. When you create a procedure so that it replaces the block on the side it works, but when you leave and enter the save again the created blocks disappear