gulp sourcemaps and clean-css not working properly

Question

The problem is I don't understand why in chrome my file name is app.css?_[sm]

I expected it to be just app.css

app.css is a minified file.

What I really want to achieve is to link the file loaded in chrome source panel to my local file.

Before I have minified and sourcemapped the file I could do this in chrome, so I could edit CSS and save to my local file on the fly.

I think the problem has something to do with that ?_[sm]parameter after the file name. So chrome is not able to link to my local file.

Here's my gulpfile:

var gulp = require('gulp');
var cleanCSS = require('gulp-clean-css');
var rename = require('gulp-rename');
var sourcemaps = require('gulp-sourcemaps');

gulp.task('minify-css', () => {
    
    return gulp.src(['../css/*.css', '../css/common/*.css'])
        .pipe(sourcemaps.init())
        .pipe(cleanCSS())
        .pipe(sourcemaps.write())
        .pipe(gulp.dest('../css/dist'));
});

gulp.task('default', ['minify-css']);