Вопрос по gulpfile.js / Did you forget to signal async completion?

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

const app = 'app/';
const dist = 'dist/';

const config = {
  app: {
    html: app + 'html/**/*.*',
    js: app + 'js/**/*.*',
    style: app + 'scss/**/*.scss',
    images: app + 'images/**/*.*',
    fonts: app + 'fonts/**/*.*',
  },
  dist: {
    html: dist,
    js: dist + 'js/',
    style: dist + 'css/',
    images: dist + 'images/',
    fonts: dist + 'fonts/',
  },
  watch: {
    html: app + 'html/**/*.*',
    js: app + 'js/**/*.*',
    style: app + 'scss/**/*.scss',
    images: app + 'images/**/*.*',
    fonts: app + 'fonts/**/*.*',
  },
};

const webServer = () => {
  browserSync.init({
    server: {
      baseDir: dist,
    },
    port: 9000,
    host: 'localhost',
    notify: false,
  });
};


const scssTask = () => {
   return gulp.src(config.app.style).pipe(
      sass()
         .on('error', sass.logError)
         .pipe(gulp.dest(config.dist.style))
         .pipe(browserSync.reload({ stream: true }))
   )
};

const watchFiles = () => {
  gulp.watch([config.watch.style], gulp.series(scssTask));
};

const start = gulp.series(scssTask);

exports.default = gulp.parallel(start, watchFiles, webServer);

Выдает ошибку, не могу понять и за чего? Пробовал в аргумент добавить done и затем его вызвать, но ничего не меняется.

[21:31:44] The following tasks did not complete: default, <series>, watchFiles, webServer, scssTask
[21:31:44] Did you forget to signal async completion?