When a double chest is place over a  chunk border (the chest is in two different chunks), half of the chest will turn invisible randomly. When the chest is opened, it will crash the world which resets it the the last saved point. In a realm, this is the last time someone joins or leaves. This can be just a few minutes, or sometimes over an hour. 

The only work around is to break the chest and place it again, but sometimes you don't realize until after already opening it, which means you could lose a lot of progress. I have both PS4 and Xbox One players on my realm, and I would imagine it affects all other versions as well. I am unaware if this is in normal local worlds too. 

I haven't found a way to recreate it. It doesn't happen when you place the chest, and it doesn't happen every time you unload the chunks either. 

In the picture, you can see how half of the top 2 chests are invisible but the outline is still there. The chest below is also on a chunk border, but it wasn't affected.