How to return the shadow to a transparent block, custom model, or how to make a block solid

I've already surfed the Internet looking for a fix for this error, I also saw how some have problems with the opposite of the shadow on the custom model, but I do not know how to call it, please help, it really breaks the mod, because the block is transparent, so it is not solid, and my entire mod is built on this variable.

Images: https://imgur.com/a/u5sKNJL

JSON block:
{
    "parent": "block/block",
    "textures": {
        "particle": "mod/peat_dirt",
        "bottom": "mod/peat_dirt",
        "top": "mod/peat_dirt_overgrown_top",
        "side": "mod/peat_dirt_overgrown",
        "overlay": "mod/peat_dirt_overgrown_side"
    },
    "elements": [
        {
            "from": [0, 0, 0],
            "to": [16, 16, 16],
            "faces": {
                "north": {"uv": [0, 0, 16, 16], "texture": "#side", "cullface": "north"},
                "east": {"uv": [0, 0, 16, 16], "texture": "#side", "cullface": "east"},
                "south": {"uv": [0, 0, 16, 16], "texture": "#side", "cullface": "south"},
                "west": {"uv": [0, 0, 16, 16], "texture": "#side", "cullface": "west"},
                "up": {"uv": [0, 0, 16, 16], "texture": "#bottom", "cullface": "up"},
                "down": {"uv": [0, 0, 16, 16], "texture": "#bottom", "cullface": "down"}
            }
        },
        {
            "from": [0, 0, 0],
            "to": [16, 16, 16],
            "faces": {
                "north": {"uv": [0, 0, 16, 16], "texture": "#overlay", "cullface": "north", "tintindex": 0},
                "east": {"uv": [0, 0, 16, 16], "texture": "#overlay", "cullface": "east", "tintindex": 0},
                "south": {"uv": [0, 0, 16, 16], "texture": "#overlay", "cullface": "south", "tintindex": 0},
                "west": {"uv": [0, 0, 16, 16], "texture": "#overlay", "cullface": "west", "tintindex": 0},
                "up": {"uv": [0, 0, 16, 16], "texture": "#top", "tintindex": 0}
            }
        }
    ]
}