The bug

In both survival and creative mode, destroying a jukebox with a disc inside will drop the disc at the top or above the block with velocity upwards. It seems like the game uses the disc ejection feature used when you right click the jukebox. The jukebox itself drops as any other block in survival mode.

If there is a block above the jukebox, the disc will drop inside it, and could end up on top of that block instead of where expected.

See video, 1.15-pre1.mp4