I need to make sourceMaps for my mix.combine() assets but laravel mix only creates maps for default mix.js()

Code

mix.js('resources/js/app.js', 'public/js')
   .sass('resources/sass/app.scss', 'public/css').sourceMaps();

// admin
mix.styles([
   'public/themes/admin/vendor/fontawesome-free/css/all.min.css',
   'public/themes/admin/vendor/datatables/datatables.min.css',
   'public/css/print.min.css',
   'public/js/dist/summernote-bs4.css',
   'public/themes/admin/css/admin.min.css'
], 'public/css/admin.css');

mix.combine([
   'public/themes/admin/vendor/jquery/jquery.min.js',
   'public/themes/admin/vendor/datatables/datatables.min.js',
   'public/js/print.min.js',
   'public/themes/admin/vendor/bootstrap/js/bootstrap.bundle.min.js',
   'public/themes/admin/vendor/jquery-easing/jquery.easing.min.js',
   'public/themes/admin/js/demo/datatables-demo.js',
   'public/themes/admin/js/admin.min.js'
], 'public/js/admin.js').sourceMaps();


// front
mix.styles([
   'public/themes/front/css/bootstrap.min.css',
   'public/themes/front/css/mega-menu/mega_menu.css',
   'public/themes/admin/vendor/fontawesome-free/css/all.min.css',
   'public/themes/front/css/themify-icons.css',
   'public/themes/front/css/magnific-popup/magnific-popup.css',
   'public/themes/front/css/owl-carousel/owl.carousel.css',
   'public/themes/front/revolution/css/settings.css',
   'public/themes/front/css/slick/slick.css',
   'public/themes/front/css/slick/slick-theme.css',
   'public/themes/front/css/style.css',
   'public/themes/front/css/responsive.css',
], 'public/css/front.css');


mix.combine([
   'public/themes/front/js/jquery.min.js',
   'public/themes/front/js/popper.min.js',
   'public/themes/front/js/bootstrap.min.js',
   'public/themes/front/js/mega-menu/mega_menu.js',
   'public/themes/front/js/owl-carousel/owl.carousel.min.js',
   'public/themes/front/js/slick/slick.min.js',
   'public/themes/front/js/magnific-popup/jquery.magnific-popup.min.js',
   'public/themes/front/js/isotope/isotope.pkgd.min.js',
   'public/themes/front/js/jquery.appear.js',
   'public/themes/front/js/counter/jquery.countTo.js',
   'public/themes/front/revolution/js/jquery.themepunch.tools.min.js',
   'public/themes/front/revolution/js/jquery.themepunch.revolution.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.actions.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.carousel.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.kenburn.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.layeranimation.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.migration.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.navigation.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.parallax.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.slideanims.min.js',
   'public/themes/front/revolution/js/extensions/revolution.extension.video.min.js',
   'public/themes/front/js/custom.js',
], 'public/js/front.js').sourceMaps();

result

/css/app.css
/js/app.js
/js/app.js.map <-- only app.js has map file
\css\admin.css
\css\front.css
\js\admin.js
\js\front.js <-- front.js didn't create map file

Any idea?