[1.21.4] model with condition missing texture

I have a custom 3d model which works perfectly. BUT I want it to be held diffrently on the players hand when the item is being used.

My JSON file under assets/examplemod/items looks like this:

{
  "model": {
    "type": "minecraft:condition",
    "on_false": {
      "type": "minecraft:model",
      "model": "examplemod:item/example_item"
    },
    "on_true": {
      "type": "minecraft:model",
      "model": "examplemod:item/example_item_using"
    },
    "property": "minecraft:using_item"
  }
}

This works fine until the item is used. The correct model will be displayed but with a full black texture instead of the actuall texture. Any idea why? (I want to use the exact same texture for both items, because their model is the same just diffrent displays on firstperson_righthand and firstperson_lefthand). The models JSON's are fully blockbench files inlcuding the elements, display, textures with texture_size.

Also is this the correct way to do it? Because it feels so dumb to change the exact same model just for a diffrent right- and lefthand view.

(fyi: ItemUseAnimation is BLOCK for this item)

Edited January 24Jan 24 by Ezio214