Hello I have found a bug involving double chests and observers. It seems that when you load in chunks with a observer facing a double chest it causes it to update and send a redstone signal. I was testing things with command blocks so when I spawned in it gave me the effect I put in. I tested it multiple times with the same effect, it only stopped when I made it a single chest. I'm sorry if this doesn't help any, I'm just telling you what's went down.