$ pulling object from array based on _id in Mongoose

I am trying to remove an object from an array based on its _id field like this:

(messages are an array of objects)

    User.findOneAndUpdate(
    { id: req.params.userid },
    { $pull: { 'posts': { 'posts._id': { $eq: req.body.postID } } } },
    { new: true }
 )

      

        
        
        
      

    

However, it removes ALL entries in the array, even if they have different _id values ​​being referenced req.body.postID

.

Note. ... If I try this same query with a different field, for example named post, then it works fine and only deletes that post. However, I need to do this with an _id field to ensure uniqueness.

This is what the model looks like User

:

(I don't explicitly set the _id field, which is automatically assigned to it)

    let userSchema = new mongoose.Schema({
    id: String,
    displayName: String,
    posts: [
        {
            url: String,
            description: String,
            likes: [String]
        }
    ]
    });

      

        
        
        
      

    

Why is this happening and what is a possible solution?