Chests that were created in 21w44 and opened in 1.18 Pre-release are "locked" to their 21w44 state. For example, if you put a new item in a chest created in 21w44, when you go to another dimension and come back or leave the game and join back, the item will be gone and replaced with whatever was there before. This also allows for some duplication glitches. If you take an item(s) from the 21w44 chest, go to another dimension or leave the game, you will still have the item(s) in your inventory but they will also be in the chest.