Vue3 attribute pinia (store) data loss - record it

export const useStore = defineStore("main", () => {
  const customerId = ref(0)
  const customerInfo = ref({})

  if (sessionStorage.getItem('store')) {
    const storeDate = (JSON.parse(sessionStorage.getItem('store')))
    customerId.value=storeDate.customerId
    customerInfo.value= {
      ...storeDate.customerInfo
    }
  }
  window.addEventListener("beforeunload", () => {
    sessionStorage.setItem("store", JSON.stringify({
      customerId: customerId.value,
      customerInfo: {
        ...customerInfo.value
      }
    }));

  });
  return {
    customerInfo,
    customerId,
  }
})