I've spent forever troubleshooting this myself and was about to give up when I found this Ezoic article. Since joining Ezoic Leap, my images don't appear until a long time after the page loads. Found out its because I didn't disable asynchronous loading from a plugin I already had. Once I disabled it and cleared my cache, images lazy-loaded like they are supposed to. Hope this helps someone else out there: https://support.ezoic.com/kb/article/images-appear-only-after-the-page-has-been-loaded-for-several-seconds-how-do-i-fix-this