Problems Lazy Loading With Smush

Been trying to get lazy loading to work for a while now and for the longest time it only did so with the only two png images on the site but after reading up on the posts, I’ve came to the realization that the plugin doesn’t prioritize png so something else is causing the error.

By repeatedly checking the site over on Page Speed Insights and tweaking the plugin settings, I got it to work but after a few more scans and no changes it stopped working again.

Now got it to work again, didn’t do any additional changes, just kept re-scanning and after about 10 scans, the problem occurs once again but this time without any changes to the plugin settings.

WHat could be causing this and how to fix it?

The page I need help with: [log in to see the link]