Updated a bit to make it clearer.

src/converse-muc.js

@@ -1773,15 +1773,12 @@
                     }
                     var show_status_messages = true;
                     var is_self = pres.querySelector("status[code='110']");
-                    var new_room = pres.querySelector("status[code='201']");
-
+                    var locked_room = pres.querySelector("status[code='201']");
                     if (is_self) {
                         this.saveAffiliationAndRole(pres);
-                    }
-                    if (is_self && new_room) {
+                        if (locked_room) {
                             // This is a new room. It will now be configured
-                        // and the configuration cached on the
-                        // Backbone.Model.
+                            // and the configuration cached on the Backbone.Model.
                             if (_converse.muc_instant_rooms) {
                                 this.createInstantRoom(); // Accept default configuration
                             } else {
@@ -1792,7 +1789,9 @@
                                     show_status_messages = false;
                                 }
                             }
-                    } else if (!this.model.get('features_fetched') &&
+                        }
+                    }
+                    if (!locked_room && !this.model.get('features_fetched') &&
                             this.model.get('connection_status') !== Strophe.Status.CONNECTED) {
                         // The features for this room weren't fetched yet, perhaps
                         // because it's a new room without locking (in which