Please check how it works with the default WordPress theme just to check whether the issue is with our theme or not.
If it works fine with the default WordPress theme then deactivate all the third party plugins and tell me then we will troubleshoot with the theme plugins.
Your issue has been solved. I have deactivated all the 3rd party plugins from the site and activate only theme required plugins now the slider is showing fine. So It means there is an issue created because of any 3rd party plugin, please activate the plugins one by one and check which plugin created the problem for you.