Breaking shulker boxes under creating mode in a debug world cause dropping of item shulker boxes

In the creating mode, there is no big problem when I break other blocks in a debug world. But, when I was trying to break shulker boxes, item shulker boxes have been dropped.

The video I recorded is too big, so I have to put the video on google drive 😛

P.S.: Don't care about what idiot things I've embarrass myself at the start of the video

Link: https://drive.google.com/open?id=13s6D1DxLAm9HMUMs8a1FWKbDeOmd0jj8

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