Learning to make a console roguelike for fun - collision help

[tawdry moon]

This is my movement function and collision checker

int Engine::isCollision(int x, int y, int z)
{
    if (collision_map[x][y][z] == 0)
    {
        return 0;
    }
    if (collision_map[x][y][z] == 1)
    {
        return 1;
    }
}

int Inputs::input_handler(int x, int y, int z, int cpf)
{
    constexpr auto KEY_UP = 72;

    constexpr auto KEY_DOWN = 80;

    constexpr auto KEY_LEFT = 75;

    constexpr auto KEY_RIGHT = 77;

    constexpr auto ESC = 27;
    
    int checkx = x;
    int checky = y;
    int checkz = z;

    char input_ = _getch();

    if (input_ == KEY_UP) {

        checky -= 1;

        if (isCollision(checkx, checky, checkz) == 1)
        {
            y -= 0;
            std::cout << "I can't do this";
        }
        if (isCollision(checkx, checky, checkz) == 0)
        {
            y -= 1;
        }
        
    }
//other key inputs removed for brevity
}

[cyan crow]

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[tawdry moon]

This function initializes three different arrays. One used to draw symbols to the console, one used to track the player so I don't have to erase positions in the original array when the player moves, and one used to mark what symbols positions have collision.

void Engine::create_world(int x1, int y1, int z1)
{
    height = 10;
    length = 10;
    depth = 5;
    
    Tiles map_tile;
    map_tile.wall = '#';
    map_tile.player = '@';
    map_tile.floor = '.';
    map_tile.tree = 'T';

    using Random = effolkronium::random_static;
    auto random_number = Random::get(1, 100);

    for (int y = 0; y < height; y++)
    {
        for (int x = 0; x < length; x++)
        {
            for (int z = 0; z < depth; z++)
            {
                if (x > 0 || x < length - 1)
                {
                    world_map[x][y][z] = map_tile.floor;

                    if (world_map[x][y][z] == map_tile.floor)
                    {
                        auto random_number = Random::get(1, 100);

                        if (random_number <= 10 && z == 0)
                        {
                            world_map[x][y][z] = map_tile.tree;

                        }
                    }
                }

                if (x == 0 || x == length - 1 || y == 0 || y == height - 1) //flags the perimeter of the map and puts walls
                {
                    world_map[x][y][z] = map_tile.wall;

                }

                if (x == x1 && y == y1 && z == z1)
                {
                    entity_map[x][y][z] = map_tile.player;
                }

                
                if (world_map[x][y][z] == map_tile.tree || world_map[x][y][z] ==  map_tile.wall)
                {
                    collision_map[x][y][z] = 1;
                }
                if (world_map[x][y][z] == map_tile.floor)
                {
                    collision_map[x][y][z] = 0;
                }

            }
        }
    }


}

The issue is that I know the array for collision (collision_map) is being initialized correctly, but my input_handler function doesn't seem to check it correclt and I don't know why. I can move over symbols that I shouldn't be able to