Filtering MongoDB document keys - node.js

Question

I am using Mongo 5.0.6 and have a document structured like this:
[
{
username: "admin",
properties: {
bookmarks: {
value: [
1,
2,
3
]
},
landmark: {
value: [
"home"
]
},
other: {
value: "should not show"
}
}
}
]
I need to query data based on the properties keys, this works fine in my mongo playground: https://mongoplayground.net/p/lEiLeStWGTn when I query for key that contain mark.
db.collection.aggregate([
{
$match: {
username: "admin"
}
},
{
$addFields: {
filtered: {
$filter: {
input: {
$objectToArray: "$properties"
},
cond: {
$regexMatch: {
input: "$$this.k",
regex: "mark"
}
}
}
}
}
},
{
$project: {
_id: 0,
properties: {
$arrayToObject: "$filtered"
}
}
}
])
However when I use it through my mongoose object I get [] even so the data is exactly as in playground. I am using locally the latest mongoose6 and mondodb5.0.6. I get the same [] result when I run the query against a mongodb.com hosted database. What could be the problem?
My javascript query below, I tried both using mongoose and the driver directly, as shown below:
const data= User.collection.aggregate([
{
$match: {
username: "admin"
}
},
{
$addFields: {
filtered: {
$filter: {
input: {
$objectToArray: "$properties"
},
cond: {
$regexMatch: {
input: "$$this.k",
regex: "mark"
}
}
}
}
}
},
{
$project: {
_id: 0,
properties: {
$arrayToObject: "$filtered"
}
}
}
]);
for await (const doc of data) {
console.log(doc);
}
Always gives me:
{ properties: {} }
When I take out the $addFields and $project like this:
const data= User.collection.aggregate([
{
$match: {
username: "admin"
}
}
]);
for await (const doc of data) {
console.log(doc);
}
I get, so the data is there, but aggregation pipeline isn't working:
[
{
_id: "61b9f2f5d2a6021365aae6d6",
username: "admin",
properties: {
bookmarks: {
value: [
1,
2,
3
]
},
landmark: {
value: [
"home"
]
},
other: {
value: "should not show"
}
}
}
]
So the data is there. What am I missing? Do I need to write the query differently?