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Are you sure the shulker box didn't turn invisible?

Could it be similar to the chest disappearing bug?

I've had the same issue on a realm. I broke 8 shulkers replaced them within 20 seconds 20 blocks away. There was a resource update for the server, everyone got kicked. I logged back in and they were no longer in the world where I had placed them or in my inventory.They were not in the previous positions either. They just vanished.

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