【报Bug】$getAppMap 无法获取到原生地图对象

示例代码：

<template>  
    <view class="body">  
        <map v-if="showMap" id="covering-map" ref="covering-map" :scale="16" style="height: 100%;width: 100%;"  
            :show-location="true" :latitude="latitude" :longitude="longitude" show-compass="true"  
            @updated="onMapUpdated">  
        </map>  

        <view class="confirm-btn-view">  
            <uv-button type="primary" text="确定" customStyle="width:90%" @click="confirmPosition"></uv-button>  
        </view>  
    </view>  
</template>  

<script>  
    export default {  
        data() {  
            return {  
                mapContext : null,  
                baseMap : null,  
                showMap: false,  
                latitude: 39.909,  
                longitude: 116.39742,  
            }  
        },  
        async onLoad() {  
            let res = await uni.getLocation({  
                type: "wgs84 "  
            });  
            this.latitude = res.latitude  
            this.longitude = res.longitude;  
            this.showMap = true;  
            console.log("onLoad")  
        },  
        onReady() {  
            this.mapContext = uni.createMapContext('covering-map', this)  
        },  
        methods: {  
            confirmPosition() {  
                console.log("confirmPosition")  
                console.log(this.mapContext.$getAppMap())  
            },  
            // 地图加载完成触发  
            onMapUpdated() {  
                console.log("onMapUpdated")  
                console.log(this.mapContext.$getAppMap())  
                this.mapContext.moveToLocation();  
            }  
        }  
    }  
</script>  

<style scoped>  
    page {  
        height: 100%;  
    }  

    .body {  
        width: 100%;  
        height: 100%;  
        display: flex;  
        flex-direction: column;  
        position: relative;  
    }  

    .confirm-btn-view {  
        width: 100%;  
        position: absolute;  
        bottom: 100rpx;  
        opacity: 0.8;  
    }  
</style>

操作步骤：

略

预期结果：

与IOS一样，获取到 原生地图对象

实际结果：

IOS有值，H5无值