UPDATE: I found the fix! WORKS PERFECTLY: On this page
https://kriesi.at/support/topic/advanced-layout-builder-in-events-created-with-the-events-calendar-pro-plugin/
Hello – I am having the same problem after upgrading to the latest Enfold theme Version: 4.6.3.1. The “Advanced Layout Editor” button no longer shows up when I create a new Event using The Events Calendar Plugin. It was working before, and I need all the templates in the Advanced Editor within The Events Calendar. Can you please advise ? The “Advanced Layout Editor” button is still working properly when I create a new page, and my templates are there, etc.