I did some research and found that it has become a thing where items you don't take out of a chest are automatically put into your inventory. Personally, I very much like this new feature. It has happened to me in the past that I closed a chest before taking out all items or the server restarted before I could take the items. This way, chest runs can be a lot more efficient since you dont need to spend all that time taking out all of the items individually.
I do however understand that some people might find this frustrating. So instead of this being removed alltogether, I would personally like to see this being a toggleable setting in /me