?のついたURLに飛んでしまう

Question

前提・実現したいこと

フロントをVue.js, サーバーをrailsで開発しています。
v-btnタグの登録ボタンをクリックしてregisterメソッドが成功したときに
this.$router.push({ name: 'LoginIndex' })というコードでログインページに遷移させたいのですが、
URLが /register?に飛んでしまいます
画像

該当のソースコード

javascript/pages/register/index.vue

<template>
<div id="register-form" class="form-wrapper">
  <div class="form-card">
    <div class="register">ユーザー登録</div>
    <ValidationObserver class="form-input" v-slot="{ handleSubmit }">
      <form>
        <ValidationProvider
          name="メールアドレス"
          rules="required|email"
          v-slot="{ errors }">
            <v-text-field
              id="email"
              v-model="user.email"
              :error-messages="errors"
              label="メールアドレス"
              required
            ></v-text-field>
        </ValidationProvider>
        <ValidationProvider
          name="パスワード"
          rules="required|min:8"
          v-slot="{ errors }">
          <v-text-field
            ref="password"
            id="password"
            v-model="user.password"
            :error-messages="errors"
            label="パスワード"
            required
            :append-icon="show1 ? 'mdi-eye' : 'mdi-eye-off'"
            :type="show1 ? 'text' : 'password'"
            @click:append="show1 = !show1"
          ></v-text-field>
        </ValidationProvider>
        <ValidationProvider
          name="パスワード（確認）"
          rules="required|min:8"
          v-slot="{ errors }">
          <v-text-field
            id="password_confirmation"
            v-model="user.password_confirmation"
            :error-messages="errors"
            label="パスワード（確認）"
            required
            :append-icon="show2 ? 'mdi-eye' : 'mdi-eye-off'"
            :type="show2 ? 'text' : 'password'"
            @click:append="show2 = !show2"
          >
          </v-text-field>
        </ValidationProvider>
        <v-btn type="submit" width="18%" color="primary" @click="handleSubmit(register)">登録</v-btn>
        <v-btn width="18%" color="red" dark @click="clear">消去</v-btn>
      </form>
    </ValidationObserver>
    <div class="login-link">
      <router-link to="/login">ログインはこちらから</router-link>
    </div>
  </div>
</div>
</template>

<script>
export default {
  name: "RegisterIndex",
  data() {
    return {
      show1: false,
      show2: false,
      user: {
        email: '',
        password: '',
        password_confirmation: ''
      }
    }
  },
  methods: {
    handleShowRegisterAlert(){
      this.isVisibleRegisterAlert = true;
    },
    register() {
      this.$axios.post('users', { user: this.user })
        .then(res => {
          this.$router.push({ name: 'LoginIndex' })
        })
        .catch(err => {
          console.log(err)
        })
    },
    clear () {
      this.user.email = ''
      this.user.password = ''
      this.user.password_confirmation = ''
      this.$refs.observer.reset()
    },
  },
}
</script>

javascript/router/index.js

import Vue from 'vue'
import Router from 'vue-router'
import store from '../store'

import ItemIndex from '../pages/item/index'
import RegisterIndex from '../pages/register/index'
import LoginIndex from '../pages/login/index'
import DeleteListIndex from '../pages/delete_list/index'
import NotFound from '../components/shared/NotFound'

Vue.use(Router)

const router = new Router({
  mode: 'history',
  routes: [
    {
      path: '/',
      component: ItemIndex,
      name: 'ItemIndex',
      meta: { requiredAuth: true },
    },
    {
      path: '/register',
      component: RegisterIndex,
      name: 'RegisterIndex',
    },
    {
      path: '/login',
      component: LoginIndex,
      name: 'LoginIndex',
    },
    {
      path: '/delete-list',
      component: DeleteListIndex,
      name: 'DeliteListIndex',
      meta: { requiredAuth: true }
    },
    {
      path: '*',
      component: NotFound,
      name: 'NotFound'
    }
  ],
})

router.beforeEach((to, from, next) => {
  store.dispatch('users/fetchAuthUser').then((authUser) => {
    if (to.matched.some(record => record.meta.requiredAuth) && !authUser) {
      next({ name: 'LoginIndex' });
    } else {
      next();
    }
  })
});

export default router

ご教授お願いします