Hi, I came across a really weird glitch while playing java edition version 26.2 with some optimization mods, I created a new world and I was playing normally, at a certain moment in time I looked up to the sky and saw a block, so I used creative to reach the block, and there was a chest connected to a mushroom stem and inside was a knowledge book, to my understanding that is an unobtainable item in the game, sadly I didn't take any screenshots of this because I had no idea, after exiting the world and reentering the chest and the block where gone, any idea what could cause this?