This is a fresh install. I'd follow your compatibility guide but it's out of date. I just finished updating to 6.2.3/3.2.3 and the problem is still persisting.
I've cleared the style cache (again), increased the PHP limit, there is no .htaccess in my public_html folder - not that it matters, the visual editor (drag & drop editor?) was working fine prior to the last update.
The only plugin installed is cornerstone aside from the 2 default wordpress plugins (Akismet and Dolly).
Funny enough, updating to 6.2.3 broke my child theme, so I had to delete it. Before I reinstalled it, I checked the drag n' drop builder, it's still broken.
Without any useful error messages in the console, I'm at a loss. The only thing I can think of doing is wiping the slate clean and trying again. Short of doing that, please see my private note. I have launched a tunnel so that you may check it out yourself.