diff --git a/docs/changelog.rst b/docs/changelog.rst
index bf3bba24..dfed5f59 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -5,7 +5,7 @@ Changelog
 Development
 ===========
 - expose `mongoengine.connection.disconnect` and `mongoengine.connection.disconnect_all`
-- POTENTIAL BREAKING CHANGE: Fixes in connect/disconnect methods #565 #566
+- POTENTIAL BREAKING CHANGES: Fixes in connect/disconnect methods #565 #566 #605 #607 #1213 #1599
     - calling `connect` 2 times with the same alias and different parameter will raise an error (should call disconnect first)
     - disconnect now clears `mongoengine.connection._connection_settings`
     - disconnect now clears the cached attribute `Document._collection`
diff --git a/mongoengine/connection.py b/mongoengine/connection.py
index 0597199b..8902bbf6 100644
--- a/mongoengine/connection.py
+++ b/mongoengine/connection.py
@@ -10,6 +10,8 @@ __all__ = ['MongoEngineConnectionError', 'connect', 'disconnect', 'disconnect_al
 
 DEFAULT_CONNECTION_NAME = 'default'
 DEFAULT_DATABASE_NAME = 'test'
+DEFAULT_HOST = 'localhost'
+DEFAULT_PORT = 27017
 
 if IS_PYMONGO_3:
     READ_PREFERENCE = ReadPreference.PRIMARY
@@ -61,8 +63,8 @@ def _get_connection_settings(
     """
     conn_settings = {
         'name': name or db or DEFAULT_DATABASE_NAME,
-        'host': host or 'localhost',
-        'port': port or 27017,
+        'host': host or DEFAULT_HOST,
+        'port': port or DEFAULT_PORT,
         'read_preference': read_preference,
         'username': username,
         'password': password,
@@ -172,6 +174,7 @@ def register_connection(alias, db=None, name=None, host=None, port=None,
 def disconnect(alias=DEFAULT_CONNECTION_NAME):
     """Close the connection with a given alias."""
     from mongoengine.base.common import _get_documents_by_db
+    from mongoengine import Document
 
     if alias in _connections:
         get_connection(alias=alias).close()
@@ -180,7 +183,7 @@ def disconnect(alias=DEFAULT_CONNECTION_NAME):
     if alias in _dbs:
         # Detach all cached collections in Documents
         for doc_cls in _get_documents_by_db(alias, DEFAULT_CONNECTION_NAME):
-            if hasattr(doc_cls, '_disconnect'):
+            if issubclass(doc_cls, Document):     # Skip EmbeddedDocument
                 doc_cls._disconnect()
 
         del _dbs[alias]
diff --git a/tests/test_connection.py b/tests/test_connection.py
index 827829b5..5ff22e06 100644
--- a/tests/test_connection.py
+++ b/tests/test_connection.py
@@ -249,9 +249,15 @@ class ConnectionTest(unittest.TestCase):
         connect('mongoenginetest')
 
         self.assertEqual(len(connections), 1)
-        self.assertEqual(len(dbs), 1)
+        self.assertEqual(len(dbs), 0)
         self.assertEqual(len(connection_settings), 1)
 
+        class TestDoc(Document):
+            pass
+
+        TestDoc.drop_collection()  # triggers the db
+        self.assertEqual(len(dbs), 1)
+
         disconnect()
         self.assertEqual(len(connections), 0)
         self.assertEqual(len(dbs), 0)
diff --git a/tests/test_context_managers.py b/tests/test_context_managers.py
index 227031e0..22c33b01 100644
--- a/tests/test_context_managers.py
+++ b/tests/test_context_managers.py
@@ -37,14 +37,15 @@ class ContextManagersTest(unittest.TestCase):
 
     def test_switch_collection_context_manager(self):
         connect('mongoenginetest')
-        register_connection('testdb-1', 'mongoenginetest2')
+        register_connection(alias='testdb-1', db='mongoenginetest2')
 
         class Group(Document):
             name = StringField()
 
-        Group.drop_collection()
+        Group.drop_collection()         # drops in default
+
         with switch_collection(Group, 'group1') as Group:
-            Group.drop_collection()
+            Group.drop_collection()     # drops in group1
 
         Group(name="hello - group").save()
         self.assertEqual(1, Group.objects.count())