I keep having this huge problem on one of my self-hosted WordPress website. I use Elementor plugin for adding dynamic content and widget. I also have the WordPress WP Super Cache plugin installed to speed up the page load time.
However, I just can't seem to make Elementor work without deactivating WP Super Cache plugin. So there must be some conflict between the two plugins. And I compare the plugin setting on two of my sites running the same plugins, I found the problem.