Difficulty with extending Group objects in phaser 3 (Bugs?)

Phaser 3
1

Hello!
Thanks for reading.

I have been having quite a difficult time making use of group objects… I have a group of walls, and my first wall is created at a different Y coordinate than the others! I am using the latest stable version, but this issue was not present on v3.18.1
Here’s a screnshot:

CroppedWallsBugged
CroppedWallsBugged881×511 77.2 KB

I have some code that looks like this following:

export default class Walls extends Phaser.Physics.Arcade.Group {

constructor(scene) {
    super(scene.physics.world, scene);
    this.key = 'walls'
    this.maxSize = 3; // FIXME  NOTE that the config option is notttt accepting this
    this.scene = scene;
    this.destroyed = 0;
}

add(child, addToScene) {
    if (!this.isFull() && child instanceof Wall) {
        let retVal = super.add(child, false);
        child.spawn();
        return retVal;
    }

    return super.add(child, false);
}

update() {
    // Destroy old wall
    let firstWall = this.getFirstAlive();
    if (firstWall != null && firstWall.x - firstWall.width < 0) {
        this.killAndHide(firstWall);
        this.remove(firstWall);
        firstWall.destroy(); // TODO I wonder if this is necessary
        this.destroyed++;
        this.scene.events.emit("score++");
    }

    // create new wall // TODO add some variation here?
    let lastWall = this.getLast(true);
    if (lastWall == null || lastWall.x + lastWall.width < this.scene.config.width/2) {
        this.add(new Wall(this.scene, this.scene.config.width+45, 450, IMAGES.wall));
    }
}

And the following child class:

export default class Wall extends Phaser.Physics.Arcade.Image {

constructor(scene, x, y, texture, frame) {
    super(scene, x, y, texture, frame);
    this.scene = scene;
}

spawn() {
    this.scene.add.existing(this);
    this.scene.physics.add.existing(this);

    this.setDragX(0);
    this.setImmovable(true);
    this.setVelocityX(3 * 58.66 * -1); // FIXME static constant

    return this;
}
}

Note that I am trying to make use of the maxSize parameter, which for some reason refuses to be made use of in the config… The maxSize parameter is NOT ignored if I extend GameObject.Sprite directly, however it seems that other physics related properties become an issue. Here’s an example of what my config looked like:

super(scene.physics.world, scene, [], {
        key: 'walls',
        maxSize: 3
});

And finally here’s how im adding it to my scene:

// Walls
this.walls = new Walls(this);
this.add.existing(this.walls); // fixme??

What’s going on here? Something dumb? And besides that, stylistically, am I approaching this problem poorly / correctly and extending the correct object types?

Thanks for looking!
Greg