Ref is undefined when used in render

[chennyang]

const columnFilterRef = ref([]);
list.forEach((item) => {
let son = document.createElement('div');
const itemRef = ref();
render(
h(ColumnFilter, {
ref: itemRef, //I debug it value is alse undefined
ref_for: true,
data: [root]
}),
son
);
$(#${tableId.value} thead tr th:nth(${item})).append(son);
columnFilterRef.value.push(itemRef);
});

console.log(columnFilterRef.value)
0: RefImpl {__v_isShallow: false, dep: undefined, __v_isRef: true, _rawValue: undefined, _value: undefined}
1: RefImpl {__v_isShallow: false, dep: undefined, __v_isRef: true, _rawValue: undefined, _value: undefined}
2: RefImpl {__v_isShallow: false, dep: undefined, __v_isRef: true, _rawValue: undefined, _value: undefined}
3: RefImpl {__v_isShallow: false, dep: undefined, __v_isRef: true, _rawValue: undefined, _value: undefined}

I want to call the function of ColumnFilter,why columnFilterRef is undefined?