Uncaught ReferenceError: panelsOptions is not defined

Hi, thanks for posting your question.

There is a JavaScript error present in the browser console that’s most likely related. (https://wordpress.org/support/article/using-your-browser-to-diagnose-javascript-errors/#step-3-diagnosis)

When able, please, try a quick theme and plugin conflict test. If you temporarily switch to a default theme like Twenty Nineteen and temporarily deactivate all plugins except for Page Builder, does the issue resolve?

Thanks for the update. Next, you might try activating your theme and deactivating Page Builder as well as all other plugins. Once that’s done, check the browser console. Are errors present in red text? Here is how to check for errors https://wordpress.org/support/article/using-your-browser-to-diagnose-javascript-errors/#step-3-diagnosis. If the theme is producing JavaScript errors without any plugins activated then you could reach out to the theme authors for assistance.