Swift "expected to decode Array<Any> but found a dictionary instead." - swift

Question

I am using this code to fetch data from an API and setting some variables in my view controller and everything works fine. Since I am doing this in multiple controllers I am attempting to refactor the network call into a Service class using a completion handler to execute the necessary code for settings the view's variables. The service works fine on some of the controllers, but any controller that attempts to decode an array of objects, I get the error
typeMismatch(Swift.Array, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Array but found a dictionary instead.", underlyingError: nil))
Working
let httpURL = "https://myurl.com/api"
guard let url = URL(string: httpURL) else { return }
var request = URLRequest(url: url)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
// Setting other headers here
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let data = data else {return}
do {
let consults = try JSONDecoder().decode([Consultation].self, from:data)
DispatchQueue.main.async {
// Settings values here
self.consultationTableView.reloadData()
}
} catch let jsonErr {
print(jsonErr)
}
}
task.resume()
}
Not Working
struct Service {
static let sharedInstance = Service()
func fetchPage(url: String, completion: #escaping (Data) -> ()){
let httpURL = "https://myurl.com/api"
guard let url = URL(string: httpURL) else { return }
var request = URLRequest(url: url)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
// Other headers here
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let data = data else {return}
completion(data)
}
task.resume()
}
}
ViewController
let httpURL = "https://myUrl.com/api"
Service.sharedInstance.fetchPage(url: httpURL) { (data) in
do {
let consults = try
---> Error Happens>> JSONDecoder().decode([Consultation].self, from:data) }
} catch let jsonErr {
print(jsonErr)
}
}
Any idea why when using the service class, the error shows up?