Hi,
To troubleshoot the issue please try this guideline:
Make sure you are using the most updated versions of Elementor, WordPress & your theme. Sometimes it isn’t apparent that there is an update available. Go to Dashboard > Updates and click the Check Again button to be sure. (Make sure to back up your site).
Clear all cache: your browser’s cache, other plugins’ cache
If the issue persists, deactivate all plugins apart from Elementor. If this helps, reactivate them one by one to find the culprit.
If it didn’t help, switch your theme (temporarily) to a default WordPress theme such as Twenty Sixteen and see if it makes any difference.
From your WordPress dashboard, navigate to Elementor > Settings > Experiments. Change all of the experiments to Inactive except the Flex Box experiment. Click Save Changes.