Ah, it’s the custom excerpt.
In “Screen Options” at the top right, check the box next to “Excerpt”.
Then scroll down and you’ll see those posts have custom excerpts set which is telling WPSP to ignore the 40 word limit.
It looks like you have SiteGround caching and WP Rocket installed – it would be best to choose one and stick with it over having multiple ones.
Not sure why WP Rocket is causing issues with masonry – the script is initiating, but isn’t calculating correctly. WPSP is using the bundled WordPress masonry script, so it’s very strange that it isn’t working.