Ajax登录问题

提交登录代码

  $('#login-btn').click(function () {
            let username = $('#username').val();
            let password = $('#password').val();
            let captcha = $('#captcha').val();
            $('#refreshCaptcha').attr('src',"{{ captcha_src('admin.login') }}");
            if (username == '') {
                layer.msg('用户名不能为空', {icon: 2});
                return false;
            }
            if (password == '') {
                layer.msg('密码不能为空', {icon: 2});
                return false;
            }
            if (captcha == '') {
                layer.msg('验证码不能为空', {icon: 2});
                return false;
            }
            let data = {
                'username': username,
                'password': password,
                'captcha': captcha,
                '_token': "{{ csrf_token() }}"
            };
            $.ajax({
                url: "{{ route('admin.login') }}",
                type: "POST",
                data: data,
                headers: {
                    'X-CSRF-TOKEN': $('meta[name="_token"]').attr('content')
                },
                success: function (res) {
                    if (res.code === 1) {
                        layer.msg(res.message, {icon: 1}, {time: 2000});
                        setTimeout(function () {
                            location.href = "{{ route('admin.index') }}";
                        }, 3000)
                    }else{
                        layer.msg(res.message, {icon: 2}, {time: 2000});
                        return false;
                    }
                },
                error: function (msg) {
                    let json = JSON.parse(msg.responseText);
                    json = json.errors;
                    for (let item in json) {
                        for (let i = 0; i < json[item].length; i++) {
                            layer.msg(json[item][i], {icon: 2}, {time: 2000});
                            return false; //遇到验证错误，就退出
                        }
                    }
                }
            })
        });

登录代码

public function login(LoginRequest $request)
    {
        $username = $request->get('username');
        $password = $request->get('password');
        $result = auth('admin')->attempt(['username' =>$username,'password' => $password,'status'=> 1]);
        if($result){
            return response()->json(['message'=>'登录成功','code' => 1]);
        }else{
            return response()->json(['message'=>'用户名或密码错误','code' => 0]);
        }
    }

中间件

<?php

namespace Modules\Admin\Http\Middleware;

use App\Http\Middleware\Authenticate;
use Closure;
use Illuminate\Http\Request;
class CheckLogin extends Authenticate
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle(Request $request, Closure $next)
    {
        $login_result = auth('admin')->check();
        if(!$login_result)
        {
            return redirect()->route('admin.login');
        }
        return $next($request);
    }
}

中间件注册

路由声明

Route::prefix('admin')->group(function () {
    Route::get('login', 'LoginController@loginForm')->name('admin.login');
    Route::post('login', 'LoginController@login')->name('admin.login');
    Route::middleware(['admin.auth'])->group(function () {
        Route::get('/', 'AdminController@index')->name('admin.index');
    });
});

大佬们 这个Ajax登录到底咋回事呢？有时候能登录成功，有时候又不能登录，莫名其妙的？？？