This should be a complete list of all things that dupe: Chunk Format Entities and Block Entities
INFO: tried relogging, updating chunks, ect.
UPdate info:
When the chunk does not load, it is possible to sneak over the edge and break blocks underneath the ground.
Yes the 'waiting for chunk is bad. I could even actually shift walk over the edge of the chunk, break the block under the one I was standing on, then dig down once it loaded to find i had broken a block I should not have been able to.
This should be a complete list of all things that dupe: Chunk Format Entities and Block Entities