Get timeout with URLSession dataTask in Swift after restart app because retain cycle with delegate

I use the following code to make a HTTP requests with URLSession and dataTask, but sometimes it gives me timeouts.

I just use the URLSessionDelegate to bypass the Authentication Server Trust in one of our development servers that uses HTTPS, if I use urlSession without delegate.

This error is completely inconsistent. Sometimes it works perfect, sometimes not.

Is it possible to validate the HTTP Server with the "URLCredential(trust: challenge.protectionSpace.serverTrust!" without using a delegate ?

func fetch(with url:String, completion: @escaping (Result<Data, Error>) -> Void) {
    
    let request = URLSessionHelper.getRequestWithUrl(endpointUrl: url, httpMethod: HTTPMethod.get, jsonBodyData: nil)
    weak var session = URLSession(configuration: URLSessionHelper.sessionConfiguration, delegate: SessionDelegate.shared, delegateQueue: nil)
    session!.dataTask(with: request,  completionHandler: {
        data, response, error in
        
        guard let data = data else {
            print("nil data")
            completion(.failure(NetworkError.timeout))
            return
        }
        
        if error != nil {
            print("nil error \(error!)")
            completion(.failure(error!))
        } else {
            print("success")
            completion(.success(data))
        }
        
    }).resume()        
}

This is my SessionDelegate class

class SessionDelegate:NSObject, URLSessionDelegate
{

static var shared: SessionDelegate = {
    let instance = SessionDelegate()
    return instance
}()

//private override init() {}
    
func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
    // usado para fazer o bypass na autenticação self-signed do certificado do servidor
    // We've got a URLAuthenticationChallenge - we simply trust the HTTPS server and we proceed
    print("start didReceive challenge 1")
    completionHandler(.useCredential, URLCredential(trust: challenge.protectionSpace.serverTrust!))
}

EDIT 1

If I use

UrlSession.shared.dataTask

with a secondary data server(that uses HTTP, not HTTPS) instead of using

weak var session = URLSession(configuration: URLSessionHelper.sessionConfiguration, delegate: SessionDelegate.shared, delegateQueue: nil

everything works fine. But our clients use the HTTPS server, because of that I need to figure out how to create a code that could be used with the HTTPS server without to be locked in the retain cycle that involves URLSession and the delegate.

EDIT 2

I modify the code:

let request = URLSessionHelper.getRequestWithUrl(endpointUrl: url, httpMethod: HTTPMethod.get, jsonBodyData: nil)
    weak var session = URLSession(configuration: URLSessionHelper.sessionConfiguration, delegate: SessionDelegate.shared, delegateQueue: nil)
    session!.dataTask(with: request,  completionHandler: {
        data, response, error in
        
        guard let data = data else {
            print("nil data")
            completion(.failure(NetworkError.timeout))
            session!.finishTasksAndInvalidate()
            return
        }
        
        if error != nil {
            print("nil error \(error!)")
            completion(.failure(error!))
            session!.finishTasksAndInvalidate() // invalidateAndCancel() or finishTasksAndInvalidate()
        } else {
            print("success")
            completion(.success(data))
            session!.finishTasksAndInvalidate()
        }
        
        
    }).resume()

but the problem still persists, if I restart the app and try to call URLSession, the problem appears for me.

If I use "invalidateAndCancel()" instead of "finishTasksAndInvalidate()", the behavior is the same.