Cushions cannot be placed on top of open shulker boxes

When placed upright, the bounding box of Shulker boxes extend up at most 0.5 blocks while being opened. Attempting to place Cushions on top of this extended bounding box (while crouching, of course) fails.

This seems a more dramatic case of MC-309659 where blocks can have a bounding box extending beyond itself and failing to be respected by Cushions. The fix for 309659 extends the search range down by 0.125 blocks which turns out to be not enough.

Well, that’s how edge cakes[sic] taste.

Steps to reproduce

1. (optional) tick rate 1 so that it is easier to operate the following steps

2. Place a Shulker Box upright (facing up)

3. Open the Shulker Box and wait until it fully opens

4. Leave the Shulker Box inventory UI, and (optional) immediately tick freeze

5. Before the Shulker Box fully closes (if you tick freezeed in time this should be always the case), try to place a Cushion on top of the Shulker Box

Note that it would be easier to test in multi-player by having another player keeping the Shulker Box open.

Expected Result

The Cushion can be placed on top of the open Shulker Box.

Actual Result

The Cushion cannot be places on top of the open Shulker Box because it wrongly assumes that there is no supporting bounding box below.