There could be various reasons for this related to specific system, we will need to take a closer look into your site to provide a healthier and more precise response, please try the following basic troubleshooting steps once and if the issue persists please open a support ticket.
Deactivate all plugins that were not included with our theme
Remove all custom CSS and check any other customizations that have been performed
If using child theme, please use default parent theme to see if that fixes it.
Make sure to clear plugin and browser cache after each step.