MongoDb bulkWrite is not working for me in node.js - node.js

Question

This is my first time of using bulkWrite to carry out updates via mongoose. I am building a blog application and I am using it to learn MERN stack. I have a Post model. The Post model has object value which is an array. This is an example of it:
const PostSchema = new mongoose.Schema(
{
postLikes:{
type: Array,
default: []
}
}
)
The postLikes contain mongodb object ids of users who liked a post.
I have a logic for deleting selected users or all users by an admin. The like system does not come with a Like Model of it own. I simply used an array system inside the post model. After deleting a user, I would like to update all post models with likes of the selected users. Some users may have multiple likes across different posts.
In my node, I created a variable like this:
const {selectedIds} = req.body;
The selectedIds came from reactjs like this:
const [selectedUsers, setSelectedUsers] = useState([]);
const arrayOfSelectedUserId = (userId) =>{
setSelectedUsers(prevArray => [...prevArray, userId]);
);
}
For the request, I did it like this:
const response = await axiosPrivate.post(`/v1/users/deleteSelected`, selectedIds, { withCredentials: true,
headers:{authorization: `Bearer ${auth.token}`}})
In nodejs, the selectedUsers ids was passed to this variable:
const {selectedIds} = req.body;
I created the logic this way:
const findIntersection = (array1, array2) => {
return array1.filter((elem) => {
return array2.indexOf(elem) !== -1;
});
}
const filteredPost = posts.filter((singleFilter) => {
const intersection = findIntersection(selectedIds, singleFilter.postLikes);
return singleFilter.postLikes.length !== 0 && intersection.length !== 0;
});
const updatedPosts = filteredPost.map((obj)=>{
const intersection = findIntersection(selectedIds, obj.postLikes);
console.log(intersection )
return {
updateOne: {
filter: { _id: obj._id },
update: { $pull: { postLikes: { $in: intersection } } },
},
};
});
Post.bulkWrite(updatedPosts).then((res) => {
console.log("Documents Updated", res.modifiedCount)
})
The console.log shows the text Document updated and showed number of documents updated. However, if I check my database, the update won't reflect. This means that the selected users' ID is still in the array.
Is there a better method? What Am I doing wrong?