I hope you are well today and thank you for your question.
This can be due to plugin conflict on your site so please try temporarily 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.
If it is not plugin conflict then would you mind if I log in to your site and do some troubleshooting? If this is ok then could you please temporarily share me your site admin login details privately by adding them in the box having text “Enter your private content here (only you and forum moderators will be able to see it)”?