app端nvue 页面地图使用markers显示自定义气泡问题，如果用v-if判断ioS显示，安卓不显示，如果不用判断，安卓正常，ios不显示

<template>
<view class="index">
<map v-if="isUpdate" id="map" style="height: 800px;width:400px"
scale="14" :longitude="longitude" :latitude="latitude" :show-location="showMap" :markers="markers">
<cover-view slot="callout">
<template v-for="(item,index) in markers">
<cover-view :marker-id="item.id" :key="item.id" class="customCallout">
<cover-view>
customCallout
</cover-view>
</cover-view>
</template>
</cover-view>
</map>

</view>  
</view>  
</view>  

</template>
<script>
export default {
data() {
return {
longitude: "", //经度
latitude: "", //纬度
markers: [],
isUpdate: false
}

    },  
    methods: {  

        // 地图marker点  
        _mapMarkers() {  
            // 获取地图的点  
            let markers = [{  
                        id: 1,  
                        latitude: 40,  
                        longitude: 40,  
                        width: 40,  
                        height: 40,  
                        joinCluster: true,  
                        customCallout: {  
                            display: "ALWAYS"  

                        }  
                        }  
                    ]  
                    this.isUpdate = false;  

                    this.$nextTick(() => {  

                        this.isUpdate = true  

                        this.markers = markers  
                    });  

                },  

        },  

        onLoad() {  
            this._mapMarkers() // 地图marker点  
        }  
    }  

</script>
<style>

</style>