This can happen for many reasons. Some of them are:
Wrong page template selected
Make sure you choose Elementor Canvas as your page template.
Elementor Widget Space is set to 20 px
By default, Elementor sets 20 px space between widgets. In order to have complete control over elements we use on our pages we set the Widget Space to 0 px, and so should you if you want your template to display the same as it does on our demo pages. You can change it while you are in the editor
Your theme might be interfering with the page style
Elementor by default overrides theme styling but in some cases, theme's styling might get applied to your Elementor based page. To avoid that, we recommend switching to Elementor Hello theme.
If none of this solves the issue please contact us directly.