diff --git a/History.md b/History.md
index 2e1d6500294..91130da0e10 100644
--- a/History.md
+++ b/History.md
@@ -1,3 +1,16 @@
+5.11.15 / 2021-02-03
+====================
+ * fix(document): fix issues with `isSelected` as an path in a nested schema #9884 #9873 [IslandRhythms](https://github.com/IslandRhythms)
+ * fix(index.d.ts): better support for `SchemaDefinition` generics when creating schema #9863 #9862 #9789
+ * fix(index.d.ts): allow required function in array definition #9888 [Ugzuzg](https://github.com/Ugzuzg)
+ * fix(index.d.ts): reorder create typings to allow array desctructuring #9890 [Ugzuzg](https://github.com/Ugzuzg)
+ * fix(index.d.ts): add missing overload to Model.validate #9878 #9877 [jonamat](https://github.com/jonamat)
+ * fix(index.d.ts): throw compiler error if schema says path is a String, but interface says path is a number #9857
+ * fix(index.d.ts): make `Query` a class, allow calling `Query#where()` with object argument and with no arguments #9856
+ * fix(index.d.ts): support calling `Schema#pre()` and `Schema#post()` with options and array of hooked function names #9844
+ * docs(faq): mention other debug options than console #9887 [dandv](https://github.com/dandv)
+ * docs(connections): clarify that Mongoose can emit 'error' both during initial connection and after initial connection #9853
+
 5.11.14 / 2021-01-28
 ====================
  * fix(populate): avoid inferring `justOne` from parent when populating a POJO with a manually populated path #9833 [IslandRhythms](https://github.com/IslandRhythms)
diff --git a/docs/faq.pug b/docs/faq.pug
index 54a6636b21d..29ef6affbd2 100644
--- a/docs/faq.pug
+++ b/docs/faq.pug
@@ -293,9 +293,10 @@ block content
 
     <a href="#enable_debugging">**Q**</a>. How can I enable debugging?
 
-    **A**. Set the `debug` option to `true`:
+    **A**. Set the `debug` option:
 
     ```javascript
+    // all executed methods log output to console
     mongoose.set('debug', true)
     
     // disable colors in debug mode
@@ -305,8 +306,7 @@ block content
     mongoose.set('debug', { shell: true })
     ```
 
-    All executed collection methods will log output of their arguments to your
-    console.
+    For more debugging options (streams, callbacks), see the ['debug' option under `.set()`](./api.html#mongoose_Mongoose-set).
 
 
     <hr id="callback_never_executes" />
diff --git a/index.d.ts b/index.d.ts
index ff2b9c49019..e349d0cd652 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -630,11 +630,11 @@ declare module 'mongoose' {
     countDocuments(filter: FilterQuery<T>, callback?: (err: any, count: number) => void): Query<number, T>;
 
     /** Creates a new document or documents */
-    create<DocContents = T | DocumentDefinition<T>>(doc: DocContents): Promise<T>;
     create<DocContents = T | DocumentDefinition<T>>(docs: DocContents[], options?: SaveOptions): Promise<T[]>;
+    create<DocContents = T | DocumentDefinition<T>>(doc: DocContents): Promise<T>;
     create<DocContents = T | DocumentDefinition<T>>(...docs: DocContents[]): Promise<T[]>;
-    create<DocContents = T | DocumentDefinition<T>>(doc: DocContents, callback: (err: CallbackError, doc: T) => void): void;
     create<DocContents = T | DocumentDefinition<T>>(docs: DocContents[], callback: (err: CallbackError, docs: T[]) => void): void;
+    create<DocContents = T | DocumentDefinition<T>>(doc: DocContents, callback: (err: CallbackError, doc: T) => void): void;
 
     /**
      * Create the collection for this model. By default, if no indexes are specified,
@@ -1382,7 +1382,7 @@ declare module 'mongoose' {
      * path cannot be set to a nullish value. If a function, Mongoose calls the
      * function and only checks for nullish values if the function returns a truthy value.
      */
-    required?: boolean | (() => boolean) | [boolean, string];
+    required?: boolean | (() => boolean) | [boolean, string] | [() => boolean, string];
 
     /**
      * The default value for this path. If a function, Mongoose executes the function
diff --git a/lib/document.js b/lib/document.js
index 6c14f869db2..042b48ed342 100644
--- a/lib/document.js
+++ b/lib/document.js
@@ -140,7 +140,6 @@ function Document(obj, fields, skipId, options) {
       });
     }
   }
-
   if (obj) {
     // Skip set hooks
     if (this.$__original_set) {
@@ -899,6 +898,7 @@ Document.prototype.overwrite = function overwrite(obj) {
  */
 
 Document.prototype.$set = function $set(path, val, type, options) {
+
   if (utils.isPOJO(type)) {
     options = type;
     type = undefined;
@@ -937,9 +937,13 @@ Document.prototype.$set = function $set(path, val, type, options) {
         path = path._doc;
       }
     }
+    if (path == null) {
+      const _ = path;
+      path = val;
+      val = _;
+    }
 
     prefix = val ? val + '.' : '';
-
     keys = Object.keys(path);
     const len = keys.length;
 
diff --git a/lib/query.js b/lib/query.js
index b115e6f17f7..21e19d205ed 100644
--- a/lib/query.js
+++ b/lib/query.js
@@ -1397,9 +1397,11 @@ Query.prototype.setOptions = function(options, overwrite) {
 Query.prototype.explain = function(verbose) {
   if (arguments.length === 0) {
     this.options.explain = true;
-    return this;
+  } else if (verbose === false) {
+    delete this.options.explain;
+  } else {
+    this.options.explain = verbose;
   }
-  this.options.explain = verbose;
   return this;
 };
 
diff --git a/package.json b/package.json
index 64ef253ecd8..2c62532081a 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "mongoose",
   "description": "Mongoose MongoDB ODM",
-  "version": "5.11.14",
+  "version": "5.11.15",
   "author": "Guillermo Rauch <guillermo@learnboost.com>",
   "keywords": [
     "mongodb",
@@ -22,7 +22,7 @@
     "@types/mongodb": "^3.5.27",
     "bson": "^1.1.4",
     "kareem": "2.3.2",
-    "mongodb": "3.6.3",
+    "mongodb": "3.6.4",
     "mongoose-legacy-pluralize": "1.0.2",
     "mpath": "0.8.3",
     "mquery": "3.2.3",
diff --git a/test/document.test.js b/test/document.test.js
index 6a9c50c13c1..dec8f31dc2f 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -9931,6 +9931,7 @@ describe('document', function() {
       assert.ok(doc);
     });
   });
+
   it('Makes sure pre remove hook is executed gh-9885', function() {
     const SubSchema = new Schema({
       myValue: {
@@ -9968,5 +9969,47 @@ describe('document', function() {
       });
       assert.equal(count, 1);
     });
+  });  
+    
+  it('gh9880', function(done) {
+    const testSchema = new Schema({
+      prop: String,
+      nestedProp: {
+        prop: String
+      }
+    });
+    const Test = db.model('Test', testSchema);
+
+    new Test({
+      prop: 'Test',
+      nestedProp: null
+    }).save((err, doc) => {
+      doc.id;
+      doc.nestedProp;
+
+      // let's clone this document:
+      new Test({
+        prop: 'Test 2',
+        nestedProp: doc.nestedProp
+      });
+
+      Test.updateOne({
+        _id: doc._id
+      }, {
+        nestedProp: null
+      }, (err) => {
+        assert.ifError(err);
+        Test.findOne({
+          _id: doc._id
+        }, (err, updatedDoc) => {
+          assert.ifError(err);
+          new Test({
+            prop: 'Test 3',
+            nestedProp: updatedDoc.nestedProp
+          });
+          done();
+        });
+      });
+    });
   });
 });
diff --git a/test/errors.validation.test.js b/test/errors.validation.test.js
index 34c9c9f7127..69a32d020e3 100644
--- a/test/errors.validation.test.js
+++ b/test/errors.validation.test.js
@@ -243,16 +243,17 @@ describe('ValidationError', function() {
   });
 
   describe('when user code defines a r/o Error#toJSON', function() {
-    it('shoud not fail', function() {
+    it('shoud not fail', function(done) {
       const err = [];
       const child = require('child_process')
-        .fork('./test/isolated/project-has-error.toJSON.js', { silent: true });
+        .fork('./test/isolated/project-has-error.toJSON.js', ['--no-warnings'], { silent: true });
 
       child.stderr.on('data', function(buf) { err.push(buf); });
       child.on('exit', function(code) {
         const stderr = err.join('');
         assert.equal(stderr, '');
         assert.equal(code, 0);
+        done();
       });
     });
   });
diff --git a/test/model.populate.test.js b/test/model.populate.test.js
index def9145cde2..97871f1ac92 100644
--- a/test/model.populate.test.js
+++ b/test/model.populate.test.js
@@ -9870,7 +9870,6 @@ describe('model: populate:', function() {
     });
   });
   it('gh-9833', function() {
-    const util = require('util');
     const Books = db.model('books', new Schema({ name: String, tags: [{ type: Schema.Types.ObjectId, ref: 'tags' }] }));
     const Tags = db.model('tags', new Schema({ author: Schema.Types.ObjectId }));
     const Authors = db.model('authors', new Schema({ name: String }));
@@ -9898,8 +9897,6 @@ describe('model: populate:', function() {
       ];
       const books = yield Books.aggregate(aggregateOptions).exec();
 
-      console.log('books = ' + util.inspect(books, false, null, true));
-
       const populateOptions = [{
         path: 'tags.author',
         model: 'authors',
@@ -9907,7 +9904,6 @@ describe('model: populate:', function() {
       }];
 
       const populatedBooks = yield Books.populate(books, populateOptions);
-      console.log('populatedBooks = ' + util.inspect(populatedBooks, false, null, true));
       assert.ok(!Array.isArray(populatedBooks[0].tags[0].author));
     });
   });
diff --git a/test/typescript/create.ts b/test/typescript/create.ts
index c20f56cc308..cb76ce45172 100644
--- a/test/typescript/create.ts
+++ b/test/typescript/create.ts
@@ -18,4 +18,11 @@ Test.create({ name: 'test' }, { name: 'test2' }).then((docs: ITest[]) => console
 Test.insertMany({ name: 'test' }).then((doc: ITest) => console.log(doc.name));
 Test.insertMany([{ name: 'test' }], { session: null }).then((docs: ITest[]) => console.log(docs[0].name));
 
-Test.create([{ name: 'test' }], { validateBeforeSave: true }).then((docs: ITest[]) => console.log(docs[0].name));
\ No newline at end of file
+Test.create([{ name: 'test' }], { validateBeforeSave: true }).then((docs: ITest[]) => console.log(docs[0].name));
+
+(async() => {
+  const [t1] = await Test.create([{ name: 'test' }]);
+  const [t2, t3, t4] = await Test.create({ name: 'test' }, { name: 'test' }, { name: 'test' });
+  (await Test.create([{ name: 'test' }]))[0];
+  (await Test.create({ name: 'test' }))._id;
+})();
diff --git a/test/typescript/schema.ts b/test/typescript/schema.ts
index c6f61667b95..4aed0505b31 100644
--- a/test/typescript/schema.ts
+++ b/test/typescript/schema.ts
@@ -23,6 +23,15 @@ const movieSchema: Schema = new Schema({
     type: String,
     enum: Genre,
     required: true
+  },
+  actionIntensity: {
+    type: Number,
+    required: [
+      function(this: { genre: Genre }) {
+        return this.genre === Genre.Action;
+      },
+      'Action intensity required for action genre'
+    ]
   }
 });
 
@@ -68,4 +77,4 @@ async function gh9857() {
   };
 
   const schema = new Schema<UserDocument, UserModel, User>(schemaDefinition);
-}
\ No newline at end of file
+}