Hi there, I think there is a bug. When a page is made “Front Page” using Elelmentor, it does not allow you to update any page changes. You will get a server 500 error.
If you duplicate that exact page and it is NOT “front page” you can make page edits and update with NO server error.
Please deactivate all the 3rd party plugins and activate only theme-required plugins on the site and then check the issue. I am sure your issue will be solved. Then Activate the 3rd party plugins one by one and check which plugin is creating the issue for you.
Otherwise, if the issue still exists then keep the 3rd party plugins deactivated and share the WP admin login details of your site so I will check and give you a possible solution.