Items disapearing

I just started a survival world and I was gathering items and I made a chest to store the extra items in and then I went out of the world and then wen I came back the chest and all the items that were in it disappeared. This happened also with a tower that I built and when I cam back it was gone. It is also happening with signs. I haven't tried other blocks other than chests, cobblestone, and signs. I can't place many blocks until this gets fixed. Can you please try to fix it as soon as possible. Thank you for taking the time to read this.