Sequelize through association attributes in Pug - express

Question

In a nutshell, I cannot access though association attributes in Pug, only id and created_at can be displayed.
I have Item and Order models, they have many to many relationship though OrderItem model which is hooked to order_items table which works correctly on an API. When orders are sent to Pug using res.render, the resulting object has items which have nested order_items as 'through attributes'. Declared 'through association' attributes in the controller are id, payment, quantity and created_at and they are all seen in the object sent to res.render.
The association is defined in the Order model as:
static associate(models) { Order.belongsToMany(models.Item, {
as:'items',
through: 'order_items',
foreignKey: 'order_id',
otherKey: 'item_id'
})
}
On the Item model, similar association is declared with a few changes. On the controller, this is how I call a specific order:
const foundOrder = await Order.findOne({
where: { id: req.params.id },
include: {
model: Item,
as: 'items',
through: { attributes: ['id', 'quantity', 'payment', 'created_at']}
}
})
In views/orders/details I wanted to view details of a specific order, in the rendered result I only got item.name, item.order_items.id and item.order_items.created_at but failed to get item.order_items.quantity or item.order_items.payment which should be on the same tree level as the id.
When I try to loop through the object and console.log(item.order_items) in the server console I see the entire nested object and indeed quantity and payment are there. They are in string format as I have been trying to see if them being INTEGER was the problem but that did not solve anything.
{
"id":"2ac16f14-75c8-4bb6-b693-f5dc825eb33e",
"quantity":"34",
"payment":"136000",
"created_at":"2022-09-22T10:30:10.000Z"
}{
"id":"b7f06b43-ac79-4fc6-8e46-01c6c5a8cfd2",
"quantity":"80",
"payment":"320000",
"created_at":"2022-09-22T10:30:10.000Z"
}
Likewise, when I put console.log(item.order_items.id) or created_at in the same style in the order page in Pug I get the values for the two items that are attached with that order.
"2ac16f14-75c8-4bb6-b693-f5dc825eb33e"
"b7f06b43-ac79-4fc6-8e46-01c6c5a8cfd2"
On the other hand, if I put in the same view/orders/details.pug the script console.log(item.order_items.quantity) instead of getting 34 and 80, I get:
unidentified
unidentified
What have I done wrong?
Is this a bug with Pug?