TypeError: u.then is not a function in Vue3+Vue router

Console Error

TypeError: u.then is not a function
    at index-CyodobdF.js:26:14273
    at Object.runWithContext (index-CyodobdF.js:14:10931)
    at we (index-CyodobdF.js:26:19934)
    at index-CyodobdF.js:26:23018

index-CyodobdF.js

function W(x, F, L) {
        Be(x);
        const k = ie.list();
        return k.length ? k.forEach(ee => ee(x, F, L)) : console.error(x), // here
        Promise.reject(x)
    }

It worked fine when running locally using ‘npm run dev’, but after deploying ‘npm run build’ using nginx, the following error occurs. After logging in as below link, an error occurs during the redirect operation using router(). I tried to solve it using the answers in the link, but in my case, it didn’t work much. Can you check if there is a problem with my router?

Also, I think there may be a problem with the code because we rushed to develop without knowing about Vue3.

/router/index.js

import { createRouter, createWebHistory } from 'vue-router'
import Marker from '@/assets/icon/filled/marker.svg'
import Book from '@/assets/icon/filled/book.svg'
import User from '@/assets/icon/filled/user.svg'
import CloseRec from '@/assets/icon/filled/close-rectangle.svg'
import Cookies from 'js-cookie'
import { logoutUser } from '@/lib/utils.js'

const router = createRouter({
    history: createWebHistory(import.meta.env.BASE_URL),
    routes: [
        {
            path: '/auth',
            component: () => import('../views/Layouts/AuthLayout.jsx'),
            redirect: '/auth/login',
            children: [
                {
                    path: 'login',
                    component: () => import('@/views/pages/LoginView.jsx'),
                    meta: {}
                },
                {
                    path: 'join',
                    component: () => import('@/views/pages/JoinView.jsx'),
                    meta: {}
                }
            ]
        },
        {
            path: '/diary',
            component: () => import('../views/Layouts/MainLayout.jsx'),
            redirect: '/diary/list',
            children: [
                {
                    path: 'list',
                    component: () => import('@/views/pages/MyDiaryView.jsx'),
                    meta: {
                        is_show: true,
                        title: '내 일기',
                        icon: Book, 
                        requiresAuth: true
                    }
                },
                {
                    path: 'write',
                    component: () => import('@/views/pages/WriteView.jsx'),
                    meta: {
                        is_show: true,
                        title: '일기 쓰기',
                        icon: Marker, 
                        requiresAuth: true
                    }
                },
                {
                    path: 'detail/:id',
                    component: () => import('@/views/pages/DetailView.jsx'),
                    meta: {
                        is_show: false,
                        title: '내 일기',
                        icon: Book, 
                        requiresAuth: true
                    }
                }
            ]
        },
        {
            path: '/account',
            component: () => import('../views/Layouts/MainLayout.jsx'),
            children: [
                {
                    path: 'info',
                    component: () => import('@/views/pages/AccountInfoView.jsx'),
                    meta: {
                        is_show: true,
                        title: '내 정보',
                        icon: User, 
                        requiresAuth: true
                    }
                },
                {
                    path: 'logout',
                    component: () => import('@/views/pages/LogoutView.jsx'),
                    beforeEnter: async (to, from, next) => {
                        try {
                            await logoutUser() 
                            next('/auth/login')
                        } catch (error) {
                            console.error('로그아웃 중 에러 발생:', error)
                            next('/auth/login') 
                        }
                    },
                    meta: {
                        is_show: true,
                        title: '로그아웃',
                        icon: CloseRec,
                        requiresAuth: true
                    }
                }
            ]
        }
    ]
})


router.beforeEach((to, from, next) => {
    const isLoggedIn = !!Cookies.get('is_login')

    if (to.path === '/') {
        next(isLoggedIn ? '/diary/list' : '/auth/login')
    } else if (to.meta.requiresAuth && !isLoggedIn) {
        Cookies.remove('is_login')
        next('/auth/login')
    } else {
        next()
    }
})

export default router