作用域插槽渲染问题，前端渲染不出来，数据是获取到的

问题遇到的现象和发生背景

接口数据获取到了的，前端渲染也写对了，就是渲染不出来

用代码块功能插入代码，请勿粘贴截图
<el-dialog :title="title" :visible.sync="open" width="1000px" append-to-body >
            <el-form ref="form" :model="form" :rules="rules" label-width="120px" height="1000px">
                <el-table :data="form.classScheduleTypeDataList" :header-cell-style="{'background-color':'#ffffff'}"
                    stripe border>
                    <el-table-column align="center" width="120">
                        <template slot-scope="scope">
                            <div>
                                {{scope.row.scheduleName}}
                            div>
                            <div>
                                {{scope.row.start}}—{{scope.row.end}}
                            div>
                        template>
                    el-table-column>
                    <el-table-column align="center" v-for="(item,index) in dayList" :key="index" :label="item"
                        width="120">
                        <template slot-scope="scope">                            
                            <el-select v-model="scope.row.courseList[index].subjectId"
                                @change="handleSelectChange(scope.row.courseList[index])" placeholder="休息">
                                <el-option v-for="subjectItem in gradeTeacherList" :key="subjectItem.subjectId"
                                    :label="subjectItem.subjectName" :value="subjectItem.subjectId" />
                  
                            el-select>
                        template>
                    el-table-column>
                el-table>
            el-form>
            <div slot="footer" class="dialog-footer">
                <el-button type="primary" @click="submitForm">确 定el-button>
                <el-button @click="cancel">取 消el-button>
            div>
        el-dialog>[]()

img

运行结果及报错内容

这些渲染是之前渲染出来的，现在不行了

img

界面没数据，同时报错了

subjectId 未定义 scope.row.courseList[index].subjectId 这个值不对