Server only restarts if I run gulp with `gulp default "default"` command

[LantosIstvan]

I have the following Gulpfile:

const server = gls.new([
  '--trace-deprecation', '--trace-sync-io', 'bin/www',
]);
gulp.task('start', () => {
  return server.start();
});

...

gulp.task('app', gulp.parallel('start', 'css', 'uglify', 'files'));

gulp.task('watch:start', () => {
  //gulp.watch(paths.app, gulp.series('start'), server.start); // restart my server
  gulp.watch(paths.app, gulp.series('start'), (file) => {
    server.notify.apply(server, [file]);
  });
});

...

gulp.task('watch', gulp.parallel('watch:start', 'watch:stylus', 'watch:css', 'watch:uglify', 'watch:files'));

gulp.task('default', gulp.parallel('app', 'watch'));

If I run gulp default, the server only restart one times only, at the first when I do any modifications for example in my app.js. Meanwhile, if I re-save multiple times my main.styl file, it will re-compile the minified CSS every single time, works as expected.

I had to run gulp default "default" to be responsive every server restart, but than I run every command two times, which I think is wasting.

I running Gulp 4 now, but it was the same with Gulp 3.