Sulfur cubes' `Size` tag defaults to 0

Summoning a mounted sulfur cube with the /summon command summons an adult sulfur cube that’s the size of a baby sulfur cube (unless it’s specifically set to summon a baby sulfur cube).

How You Can Replicate

Use this command:

/summon sulfur_cube ~ ~ ~ {IsBaby:false,Passengers:[{id:"minecraft:slime",HandItems:[{id:"minecraft:redstone_dust",count:1}]}]}

This is the exact command I used - I also tested it with different mounted mobs and held items, and with removing the “IsBaby“ NBT tag, though those haven’t affected the outcome.

Expected Result

When using the /summon command to summon a sulfur cube being ridden by any mob, the “IsBaby“ NBT tag functions correctly on the sulfur cube, and the sulfur cube is the right size.

Actual Result

When using the /summon command to summon a sulfur cube being ridden by any mob, the “IsBaby“ NBT tag still works correctly on the sulfur cube, but if an adult sulfur cube is summoned, it’s the size of a baby sulfur cube.

Another thing, related to a different part of the command, the held item wasn’t showing up (even with mobs that have arms). I don’t know if the syntax I’m using for that is outdated or something, but yeah, that also doesn’t work.

Also the screenshots below show: the command I used, before pressing enter (1st screenshot), the sulfur cube summoned by the command not being attracted by slimeballs (because it’s an adult - 2nd screenshot), and the small adult sulfur cube with a block absorbed (it’s smaller than the sand blocks next to it - 3rd screenshot).