I too am having this problem. When I try to edit my page with the page builder, the top and side menu’s opens but are unresponsive (Template, Content Blocks, Row Layouts, Basic Modules etc). I can not edit any of the content on the page.
My Theme and Plugins are up to date. I tried deactivating all plugins except Beaver Builder as suggested above but it does not make any difference. What could it be? The last time I editied my site there was no issue.