3.8.3前的版本存在该问题，个人认为是一个bug未来可能会修复。

问题点：使用官方推荐的eventTarget来处理事件。当eventTarget不在同一个类中，无法调用emit触发事件

问题代码：

GameControl.ts

import { _decorator, EventTarget, Label } from 'cc';
const eventTarget = new EventTarget();

@ccclass('GameControl')
export class GameControl extends Component {

    // 金币数量
    @property(Label)
    coinNumber: Label = null;

    protected onLoad(): void {
        eventTarget.on("addCoin", this._addCoin, this);
    }

    public _addCoin(number: number) {
        let coin = Number(this.coinNumber.string);
        coin += number;
        this.coinNumber.string = coin.toString();
    }
}

Enemy.ts

import { _decorator, CCInteger, Collider2D, Component, Contact2DType, IPhysics2DContact, Node, Vec3 } from 'cc';
const eventTarget = new EventTarget();

@ccclass('Enemy')
export class Enemy extends Component {

    start() {
        let collider = this.getComponent(Collider2D);
        if (collider) {
            collider.on(Contact2DType.BEGIN_CONTACT, this.onBeginContact, this);
        }
    }
		...
    onBeginContact (selfCollider: Collider2D, otherCollider: Collider2D, contact: IPhysics2DContact | null) {

        // 先处理自己的逻辑
        let bullet = otherCollider.node;
        let attack = bullet.getComponent(Bullet).attack;
        if (this.health - attack <= 0) {
            // 金币增加
            eventTarget.emit("addCoin", 1);
            
            this.node.destroy();
        }

        // 处理子弹
        otherCollider.node.destroy();
    }
}

解决办法：将eventTarget导出，在使用的地方导入eventTarget。

GameControl.ts

import { _decorator, EventTarget, Label } from 'cc';
// 导出
export const eventTarget = new EventTarget();

@ccclass('GameControl')
export class GameControl extends Component {

    // 金币数量
    @property(Label)
    coinNumber: Label = null;

    protected onLoad(): void {
        eventTarget.on("addCoin", this._addCoin, this);
    }

    public _addCoin(number: number) {
        let coin = Number(this.coinNumber.string);
        coin += number;
        this.coinNumber.string = coin.toString();
    }
}

Enemy.ts

import { _decorator, CCInteger, Collider2D, Component, Contact2DType, IPhysics2DContact, Node, Vec3 } from 'cc';
// 导入
import { eventTarget } from '../Game/GameControl';

@ccclass('Enemy')
export class Enemy extends Component {

    start() {
        let collider = this.getComponent(Collider2D);
        if (collider) {
            collider.on(Contact2DType.BEGIN_CONTACT, this.onBeginContact, this);
        }
    }
		...
    onBeginContact (selfCollider: Collider2D, otherCollider: Collider2D, contact: IPhysics2DContact | null) {

        // 先处理自己的逻辑
        let bullet = otherCollider.node;
        let attack = bullet.getComponent(Bullet).attack;
        if (this.health - attack <= 0) {
            // 金币增加
            eventTarget.emit("addCoin", 1);
            
            this.node.destroy();
        }

        // 处理子弹
        otherCollider.node.destroy();
    }
}

参考文章

cocos 3.8.2 诡异的emit消息BUG，整了一天，什么方法都试了