Okay, if the Header Builder is working on the new sub-domain, this means there is some issue with the previous one.
Please try the below ways to fix the issue:
Firstly ensure that you enable Header Builder in Jupiter -> Theme Options -> Header
Deactivate all the plugins and then go to Header Builder page. Clear the browser cache (ctrl+f5 or cmd+f5)
Ensure you are logged into wordpress dashboard, copy the below URL and paste it in the URL bar of the browser.
Please replace http://my-domain.com with your domain name.
Please try the above 2 individual steps and let me know if any of the 2 worked.
Also, the 3rd screenshot which you have sent is the screenshot of the Elements tab, please send the screenshot of the Console tab. Console tab is to the right of the Elements tab.