Yes, you’re right! Technically, animated elements (such as fade-in or slide-up elements) are missing the .aos-animate
class. This class is added through Javascript by aos.min.js
and initiated on page load by spectra-animations.min.js
, which are Spetra JS files. When the class is missing, the animation showing the element is not launched and the page appears broken.
There is therefore an incompatibility between SiteGround Speed Optimizer and Spectra. First of all, make sure both plugins are up to date. This issue should be fixed soon, if not already.
Otherwise, it seems that the SiteGround Speed Optimizer developers are aware of the issue and a dedicated thread exists on the official SiteGround Speed Optimizer support forum. Feel free to join the discussion by mentioning this thread. They might be interested in the details I’ve mentioned above.
Finally, you can probably re-activate SiteGround Speed Optimizer, but be sure to disable the Combine JavaScript files option, or at least add these two files to the Exclude from combination list:
- /wp-content/plugins/ultimate-addons-for-gutenberg/assets/js/spectra-animations.min.js
- /wp-content/plugins/ultimate-addons-for-gutenberg/assets/js/aos.min.js
I’d recommend disabling CSS and JavaScript combinations altogether in future, even if it says “recommended”. Combining CSS and JS files was a good practice a few years ago to improve performance, but since your site uses HTTP/2, it’s no longer recommended and is prone to bugs. See: https://www.sitepoint.com/file-bundling-and-http2/