I hope you are well today and thank you for your question.
I visited your shared site and saw the front page is displaying fine as shown in the attached screenshot.
I could confirm the issue on your site.
This can be due to plugin conflict on your site so please try temporary deactivating all plugins except Unyson plugin and WpBakery page builder plugins and see whether everything works fine and then enable the plugins one by one to see which plugin is conflicting if any.
I did as you suggested but the issue persists with just those two plugins and slider revolution activated.
I also purchased the pro version of slider revolution to see if that was the issue and installed the latest slider template for the post based slider, but the issue remains the same.
I also removed all custom code to see if that was the issue.
If you wish you can also to try and de active the plugins yourself to confirm also. Thanks!
Solution for this topic
I troubleshoot it and found out it is your Blog Slider issue as If I change this slider to any other slider in your page header settings then it is working fine as shown in the attached screenshots.
To resolve the issue, please either use any other slider or recreate the Blog Slider.