This Bug came to me while I was trying out the new snapshot in my test world, where i was building things and noticed that whenever i broke a block, the sound and particles were on cue, but the block itself dissapeared in a second. This was the same with redstone, but theres already issues on that.
It happened with almost anything that created a block update, like eating cake or farming dirt.

What i expected to happen was that the blocks had Block updates, particles, and sound on cue, but the block update took a second.

What happened is that the block update trigger items had a delay around a second.

How you can see this bug is-
1. Make A Snapshot test world
2. Go around breaking blocks or looking at Block Updatable Items