Observer detects shulker box opening

Observer facing shulker block emits 2 quick redstone pulse upon opening/closing it. First version containing this bug: 19w13a (snapshot for 1.14).

Tested on the latest version 1.14.4-pre5, and most versions since 19w13a.

There's no blockstate change when opening the container. Traditional Block Update Detectors do not detect opening shulker boxes, only observers