Weird problem with Elementor and Smart Slider 3

Weird problem with Elementor and Smart Slider 3: I’ve built a landing page for a client, which worked for some time. a few days ago I’ve realized that the slider suddenly does not load, and the site is not responsive. When trying to resolve it I was unable to edit the page with elementor – “content not found” error. Turning off some plugins, I found out that when smart slider is off the content is not shown on the site. Got any idea how to resolve the issue?