Hey.
I’ve been having the same problem with quick edit since I upgraded to a newer version on one of my sites. I’m aware of how it’s supposed to work: it was working fine before I upgraded. Site A was using an adapted version of the theme lightword, and running many plugins.
Site B is another site of mine, running the same theme and same plugins. When upgraded to the new version of wordpress, it worked completely as expected.
I fixed site A by reactivating all plugins and themes. That fixed everything.
