URLSession Returns a response with http status code 200 but an incomplete response body [closed]

When I use URLSession in a Swift iOS app to fetch data from my server I get a 200 response, but the response body is incomplete (it appears to be truncated, leading to an invalid json). When I make the same request on Postman it works as expected, returning the full response body, so the issue seems to be isolated to iOS.

I am not sure what steps to take next to debug the issue. Any help or tips would be appreciated.

class NetworkManager{
    static let shared = NetworkManager(baseUrl: "https://my-url.com");
    
    let baseUrl: URL
    let session: URLSession
    var token: String?
    
    private init(baseUrl: String) {
        // TODO: Throw well defined error
        self.baseUrl = URL(string: baseUrl)!
        
        let configuration = URLSessionConfiguration.default
        self.session = URLSession(configuration: configuration)
    }
}

class Fetcher<T, G>: ObservableObject where T: Decodable, G: Codable {
    @Published var data: T? = nil
    @Published var isLoading: Bool = false
    
    public var path: [String] { return [] }
    
    func fetchData(body: G) async
    throws {
        Task { @MainActor in
            isLoading = true
        }
        
        var url = NetworkManager.shared.baseUrl;
        
        for p in path {
            url = url.appending(path: p)
        }
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.httpBody = try? JSONEncoder().encode(body)
//        TODO: This should be handled with auth challenges
        if let token = NetworkManager.shared.token {
            request.setValue(token, forHTTPHeaderField: "Authorization");
        }
        
        // Set timezone header
        request.setValue(TimeZone.current.identifier, forHTTPHeaderField: "TIMEZONE");
        
        let (respData, response) = try await NetworkManager.shared.session.data(for: request)
        
        if let token = (response as? HTTPURLResponse)?.value(forHTTPHeaderField: "Authorization") {
            NetworkManager.shared.token = token
        }
        
        guard (response as? HTTPURLResponse)?.statusCode == 200 else {
            Task { @MainActor in
                isLoading = false
            }
            throw FetchError.badRequest
        }
        
        let temp = try JSONDecoder().decode(T.self, from: respData)
        
        Task { @MainActor in
            data = temp
            isLoading = false
        }
    }
}