findOneAndUpdate seems to be doubling my $inc count - node.js

Question

I'm trying to post a comment on to my posts for my MERN app but I'm running into an issue where the comment (Posts.findOneAndUpdate) seems to posting the comments twice. I read a few posts on SO that described the issue to be the way mongoose handles queries but I must be missing something.
If anyone could explain what I'm doing wrong I would greatly appreciate it!
Route I'm using:
router.post('/newReply/:id', async function(req, res) {
const body = req.body
if (!body) {
return res.status(400).json({
success: false,
error: 'No text entered!',
})
}
const reply = new Replies(body)
if (!reply) {
return res.status(400).json({ success: false, error: err })
}
await Posts.findOneAndUpdate(
{ _id: req.params.id },
{
"$inc": { "replies": 1 },
"$push": { "comments": reply },
},
{
new: true
},
(err) => {
if (err) {
return res.status(404).json({
success: false,
error: err,
message: 'Post not found!',
})
}
return res.status(200).json({
success: true,
id: reply._id,
message: 'Reply created!',
reply: reply.reply,
points: reply.points,
createdAt: reply.createdAt
})
})
.catch(err => console.log(err))
})
Posts Model
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
// Create Schema
const PostsSchema = new Schema({
post: {
type: String,
required: true
},
points: {
type: Number,
default: 0
},
voters: {
type: Array
},
upvotedBy: {
type: Array
},
downvotedBy: {
type: Array
},
createdAt: {
type: Date,
default: Date.now
},
replies: {
type: Number,
default: 0
},
comments: {
type: Array
},
user_id: {
type: 'string'
},
deleted: {
type: Boolean,
default: false
}
});
module.exports = Posts = mongoose.model("posts", PostsSchema);