Go to Settings → WP Rocket and select File Optimization from the left-side menu:
Save the changes, then clear the page cache.
Navigate to the page where the label should be loading. In most circumstances, this will allow the label to appear.
Turning off concatenation will have no negative impact on your site's performance, and is actually not recommended for HTTP/2 domains (which the vast majority are).
If the label still isn't loading, see our Troubleshooting Doc for more assistance.