Tilemap with varying height tiles aligned to bottom

I am creating an isometric tilemap using two tileSetImages, one with terrain tiles and the other with building tiles of double the height. I want the tile images to always align to the bottom, but it seems that by default they align to the top, causing my buildings to sink underneath the map.

Although I am not using Tiled map editor, the issue is very similar to this:

That seems to have been a rendering error that has been fixed however, so I am wondering if I am just missing some configuration somewhere?

It seems like the TileSet tileOffset property should allow me to offset the y position, but I have had no luck implementing that.

I have tried setting the tilemap origin as {x:0, y:-229} but it makes no difference.

const tileset1 = this.map.addTilesetImage('TerrainTiles', 'tilesOutside',   229, 229, 0, 0, undefined, {x:0, y:0}) as Phaser.Tilemaps.Tileset;
const tileset2 = this.map.addTilesetImage('BuildingTiles1', 'tilesBuilding1', 229, 458, 0, 0, undefined, {x:0, y:-229}) as Phaser.Tilemaps.Tileset;

I also tried adding this in the map json

         "tileheight":458,
         "tilewidth":229,
         "tileOffset":{"x": 0, "y": -229}

If anyone can let me know if this is possible and how to implement I would be very grateful.

So I figured out that my tileOffset values were not being set either way.
As a workaround I set the tileSet tileOffset after making it and it works fine. It is also worth noting that a positive number was needed, I tried both positive and negative in to original settings.

tileset1.tileOffset.y = 229;