This is more of a inconsistency issue rather than an outright bug, but the block display entity renders the block from it's bottom corner upwards.

I assume this might be because quaternion transformation is easier this way (I don't really know it too well so I apologize if my lack of understanding is the issue here)

however, i still believe that as shown in the attached example with this command:

/summon sheep ~ ~ ~ {Passengers:[{id:"block_display",block_state:{Name:"sculk_catalyst"},Passengers:[{id:"sheep",Passengers:[{id:"interaction"}]}]}]} 

it is inconsistent for the block to be pertruding to the side from its anchor, especially alongside other entities of similar properties such as the interaction entity