In the meantime I did find that if I addedoutputStyle: 'compressed' to the sass-task it now works for Chrome, but not FF.
outputStyle: 'compressed'
gulp.task( 'sass', function() {…
The easiest way to modify your WordPress URLs is via the wp-config.php file. If you’ve moved your WordPress site or are trying to test it from a temporary URL, this also might be the only method that works for you.