All,
I initially setup a cloudfront instance, later because I don't get expected results, I try both Cloudfront and Cloudflare together... I finally disable my Cloudfront CDN.
I have the same (even better) results with Cloudflare and it's free...
I don't know if the issue comes from cloufront or using both cloudfront & cloudflare but my GTMetrix and Pingdom results are much better now.