Publishing changes from background threads is not allowed; make sure to publish values from the main thread - swift

Question

I'm having an issue with a Swift function. I have my class which manages all the networking, and in there I have two functions: fetchData, which gets an array of IDs, and getPosts, which gets all posts related to those IDs via a DispatchGroup and appends them to a published array, which I will then use in the View.
The issue I'm facing is:
Publishing changes from background threads is not allowed; make sure to publish values from the main thread (via operators like receive(on:)) on model updates..
The published variable assignment is already wrapped in a DispatchQueue.main.async block. What am I missing?
import Foundation
class NetworkManager: ObservableObject {
var feedPosts: [Int] = []
#Published var posts = [Post]()
func fetchData(feedType: PostsOrderType) -> Void {
if let url = URL(string: "https://hacker-news.firebaseio.com/v0/\(feedType)stories.json") {
let session = URLSession(configuration: .default)
let task = session.dataTask(with: url) { data, response, error in
if (error == nil){
let decoder = JSONDecoder()
if let result = data {
do {
let decodedRes = try decoder.decode([Int].self, from: result)
self.feedPosts = decodedRes
self.getPosts()
} catch {
print("Decoding error: \(error)")
}
}
} else {
print("Error retrieving data: \(error!)")
}
}
task.resume()
}
}
func getPosts() -> Void {
let dGroup = DispatchGroup()
//Limited to 15 to reduce networking times
let firstTenResults = self.feedPosts[0...15]
for id in firstTenResults{
guard let url = URL(string: "https://hacker-news.firebaseio.com/v0/item/\(id).json")
else {
return
}
dGroup.enter()
URLSession.shared.dataTask(with: url){
data, response, error in
let decoder = JSONDecoder()
if let result = data {
do {
let decodedRes = try decoder.decode(Post.self, from: result)
DispatchQueue.main.async {
self.posts.append(decodedRes)
}
} catch {
print("Error decoding data: \(error)")
}
}
dGroup.leave()
}.resume()
}
}
}