the broswer cannot reload when files updates using gulp and browser-sync

I have total followed the instructions of https://browsersync.io/docs/gulp

my gulpfile.js code：

let gulp = require('gulp');
let sass = require('gulp-sass');
let browserSync = require('browser-sync').create();
let reload = browserSync.reload;

gulp.task('server', ['css'], function() {
  browserSync.init({
    server: {
      baseDir: './dist'
    }
  });

  gulp.watch('src/sass/*.scss', ['css']);
  gulp.watch("dist/*.html").on('change', reload);
  gulp.watch("dist/sass/*.css").on('change', reload);
});

// 编译Sass
gulp.task('css', function() {  // 任务名
  return gulp.src('src/sass/a.scss')  // 目标 sass 文件
    .pipe(sass())  // sass -> css
    .pipe(gulp.dest('dist/sass/'))  // 目标目录
    // .pipe(reload({stream: true}))
    .pipe(browserSync.stream());
});

gulp.task('default', ['server']);

when I update the sass file, it seems that the css file will be updated immediately, but the broswer cannot reload.

and the command line show：

It seem that the cli cannot connect to the broswer?

===

The problem is solved，my html file does not have a body tag，see https://github.com/BrowserSync/browser-sync/issues/392#issuecomment-245380582

The problem is solved，my html file does not have a body tag，see https://github.com/BrowserSync/browser-sync/issues/392#issuecomment-245380582