In-App Purchase receipt not working properly

I created an In-App Purchase subscription feature in my app, but the receipt validation is not working properly. I would like to change a boolean based on the status of the purchase (e.g. subscription is active or subscription is expired). If the subscription is active I'd like to change bool to true and enable user button interaction, if expired, then change bool to false and deny button interaction.

View did load code to set the bool:

do {
            try validateReceipt()
            // The receipt is valid 
            print("Receipt is valid")
            UserDefaults.standard.set(true, forKey: "isSubbed")
        } catch ReceiptValidationError.receiptNotFound {
            // There is no receipt on the device 
            UserDefaults.standard.set(false, forKey: "isSubbed")
        } catch ReceiptValidationError.jsonResponseIsNotValid(let description) {
            // unable to parse the json   
            print(description)
        } catch ReceiptValidationError.notBought {
            // the subscription hasn't being purchased 
            UserDefaults.standard.set(false, forKey: "isSubbed")
        } catch ReceiptValidationError.expired {
            // the subscription is expired 
            UserDefaults.standard.set(false, forKey: "isSubbed")
        } catch {
            print("Unexpected error: \(error).")
        }

Here's some code for receipt validation:

enum ReceiptValidationError: Error {
    case receiptNotFound
    case jsonResponseIsNotValid(description: String)
    case notBought
    case expired
}

func validateReceipt() throws {
    guard let appStoreReceiptURL = Bundle.main.appStoreReceiptURL, FileManager.default.fileExists(atPath: appStoreReceiptURL.path) else {
        throw ReceiptValidationError.receiptNotFound
    }
    
    let receiptData = try! Data(contentsOf: appStoreReceiptURL, options: .alwaysMapped)
    let receiptString = receiptData.base64EncodedString()
    let jsonObjectBody = ["receipt-data" : receiptString, "1111" : String()]
    
    #if DEBUG
    let url = URL(string: "https://sandbox.itunes.apple.com/verifyReceipt")!
    #else
//    let url = URL(string: "https://buy.itunes.apple.com/verifyReceipt")!
    #endif
    
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.httpBody = try! JSONSerialization.data(withJSONObject: jsonObjectBody, options: .prettyPrinted)
    
    let semaphore = DispatchSemaphore(value: 0)
    
    var validationError : ReceiptValidationError?
    
    let task = URLSession.shared.dataTask(with: request) { data, response, error in
        guard let data = data, let httpResponse = response as? HTTPURLResponse, error == nil, httpResponse.statusCode == 200 else {
            validationError = ReceiptValidationError.jsonResponseIsNotValid(description: error?.localizedDescription ?? "")
            semaphore.signal()
            return
        }
        guard let jsonResponse = (try? JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers)) as? [AnyHashable: Any] else {
            validationError = ReceiptValidationError.jsonResponseIsNotValid(description: "Unable to parse json")
            semaphore.signal()
            return
        }
        guard let expirationDate = self.expirationDate(jsonResponse: jsonResponse, forProductId: "com.test.UnlockTools.Subscription1") else {
            validationError = ReceiptValidationError.notBought
            semaphore.signal()
            return
        }
        
        let currentDate = Date()
        if currentDate > expirationDate {
            validationError = ReceiptValidationError.expired
        }
        
        semaphore.signal()
    }
    task.resume()
    
    semaphore.wait()
    
    if let validationError = validationError {
        throw validationError
    }
}
    
    func expirationDate(jsonResponse: [AnyHashable: Any], forProductId productId :String) -> Date? {
        guard let receiptInfo = (jsonResponse["latest_receipt_info"] as? [[AnyHashable: Any]]) else {
            return nil
        }
        
        let filteredReceipts = receiptInfo.filter{ return ($0["product_id"] as? String) == productId }
        
        guard let lastReceipt = filteredReceipts.last else {
            return nil
        }
        
        let formatter = DateFormatter()
        formatter.dateFormat = "yyyy-MM-dd HH:mm:ss VV"
        
        if let expiresString = lastReceipt["expires_date"] as? String {
            return formatter.date(from: expiresString)
        }
        
        return nil
    }

}

Currently the bool does not seem to change. Not sure the try and catch is working properly. I'll provide more code if needed. Any help would be greatly appreciated.