【报Bug】.inc自增运算符报错数据库验证失败：["adBalance"]类型无效

示例代码：

// mpUser.schema.json  
"adBalance": {  
            "description": "剩余广告次数余额",  
            "bsonType": "int"  
        },  

// 云对象  
async addAdBalance() {  
        let { _id, openid, otherid, num } = this.params  
        const dbCmd = db.command  
        const res = await dbJQL.collection('mpUser')  
            .where({ _id: _id, openid: openid, otherid: otherid })  
            .update({ adBalance: dbCmd.inc(1) })  
        return getResult({  
            data: res  
        })  
    },  

// 调用  
const uniMpCloud = uniCloud.importObject('uni-mp', { customUI: true })  
uniMpCloud.addAdBalance({  
            openid: userInfo.value.openid,  
            num: 1  
        }).then(res2 => {  
            console.log(res2);  
        })

操作步骤：

调用就复现

预期结果：

正常自增

实际结果：

报错