mongoose model refuses to update array of objects inside array of objects - node.js

Question

I've a schema for a store inventory. The location has locationcategories array in the schema and inside that array, I have items[] array.
My issue is updating this items[] inside the locationcategories[]. I use the mongodb shell to update that array (using updateOne()) and it works (update my items[] inside locationcategories[]) but when I do it using mongoose model ("Locations") it doesn't update, in my console, it just shows { n: 1, nModified: 0, ok: 1 } which indicate that everything was found but didn't modify anything. When I check the db, it doesn't have any new items added.
Here is code I use in mongoshell which updates items[] inside locationcategories[]
db.locations.updateOne({"locationname" :"My Town", "locationcategories":{"$elemMatch":{"categoryname": "Media"}}},{$push:{"locationcategories.$.items": {"test":"test"}}})
In my application server route (expressjs) I enter the following:
Location.updateOne(
{ "locationname": "My Town", "locationcategories": {"$elemMatch":{"categoryname": "Media"}}},
{$push: {"locationcategories.$.items": {"test":"test"}}},
{new : true, upsert: true },
function (error, results) {
console.log("findByIdAndUpdate results :", results);
}
);
my mongooose schema-model:
var Schema = mongoose.Schema;
var locationSchema = new Schema({
locationname: String,
locationdescription: String,
locationcategories: [{ categoryorder: Number, categoryname: String,
categorydescription: String, items[{itemname: String }]}],
items: [{categoryid : String, itemorder: Number, itemname: String, itemdescription: String, itemprice: Number }],
created_at: Date
});
var Location = mongoose.model('Location', locationSchema);
export default Location;
I'm using mognodb version 4.02
Model.updateOne should work but it is not adding anything to my db. I read many of the stackoverflow.com issues but I couldn't find anything that indicate an issue except this old question from years ago which he had an issue updating array inside array. I find it hard to believe that there is an issue and no one addressed it after all those years but I might be wrong.
If the mongo shell execute and add to db correctly, it leads me to believe that the mongoose model or schema are responsible for the issue or my updateOne() code is wrong.
Any idea why?

Answer 1

Got it. So I changed items inside the locationcategories[] to categoryItems[] and it works.
The .$ operator looks for the first array with the name items which was items outside but I was posting the data to the model's first array.
Make sure you name the arrays in your model with unique names and point the $push to the correct array.
Also upgrded mongodb from version 4.0 to the latest one 4.41.