Preload Key Request Warning

I am using SG Optimzier and when I run google pagespeed I get a preload key request issue with a warning of
Warnings: A preload <link> was found for "https://littlediscoverer.com/wp-content/uploads/siteground-optimizer-assets/siteground-optimizer-combined-js-e6adfba844895d16582bb1ad68e81bb7.js" but was not used by the browser. Check that you are using thecrossoriginattribute properly.

This is only when I enable the defer render blocking JS feature. Please help!