only in patch2:
unchanged:
--- a/core/modules/quickedit/js/quickedit.js
+++ b/core/modules/quickedit/js/quickedit.js
@@ -272,7 +272,7 @@
     // outside of "the entity DOM node": it's rendered as the page title. So in
     // this case, we must find the entity in the mandatory "content" region.
     if (entityElement.length === 0) {
-      entityElement = $('.region-content').find(entityElementSelector);
+      entityElement = $('main').find(entityElementSelector);
     }
     var entityInstanceID = entityElement
       .get(0)