Big Custom Models show dark

I have a Custom Model that appears darker than it should.
In 1.15 Pre-release 2 it was just fine.

give :

give @p minecraft:red_stained_glass_pane{CustomModelData:25390002}

red_stained_glass_pane.json :

{    
   "parent": "item/handheld",
   "textures": {   "layer0": "block/red_stained_glass"   },
   "overrides": [
      { "predicate": {"custom_model_data": 25390001}, "model":"item/invisible"},
      { "predicate": {"custom_model_data": 25390002}, "model":"gui/crafting_gui"}
   ]
}

gui/cafting_gui.json :

{
	"textures": {
		"0": "gui/crafting_gui",
		"particle": "gui/crafting_gui"
	},
	"elements": [
		{
			"from": [-16, 0, 0],
			"to": [32, 21.494, 0],
			"faces": {
				"north": {"uv": [0, 0, 16, 7.09063], "texture": "#0"},
				"east": {"uv": [0, 0, 0, 8], "texture": "#missing"},
				"south": {"uv": [0, 0, 16, 7.08906], "texture": "#0"},
				"west": {"uv": [0, 0, 0, 8], "texture": "#missing"},
				"up": {"uv": [0, 0, 16, 0], "texture": "#missing"},
				"down": {"uv": [0, 0, 16, 0], "texture": "#missing"}
			}
		}
	],
	"display": {
		"ground": {
			"scale": [0.05, 0.05, 0.05]
		},
		"gui": {
			"translation": [72, -20, 2.5],
			"scale": [3.65, 3.65, 3.65]
		}
	}
}