Search not working with object data

[himanshutecstub]

Do you want to request a feature, an issue, or report a bug?
Yes

What is the current behaviour?
Can't search with index and object data

If the current behaviour is a bug, please provide the steps to reproduce.
I create user Schema with fuzzy search plugin as below

const UserSchema = new Schema({
  name: {
    firstName: String,
    lastName: String
  },
  email: String
},{timestamps: true});
UserSchema.index({"$**": "text"});
UserSchema.plugin(mongoose_fuzzy_searching, { fields: ['name.firstName', 'name.lastName', 'email'] });
const User = mongoose.model('User', UserSchema);

When try to search with firstname or last name it's return no results while already have results
User.fuzzySearch({query: 'jo'}).sort({ age: -1 }).exec();
Also check in mongoose database email_fuzzy have data but firstName_fuzzy haven't data

What is the expected behaviour?
Return results when add data as new User({ email : "[email protected]",name : {firstName: 'John A', lastName: 'Deo'}});
If this is a feature request, what is the motivation or use case for changing
the behaviour?
No
Please mention other relevant information such as Node.js and mongoose version.
Node : 16.6.2
Mongoose : 5.10.19