SDKBOX IAP long timeout and connection failure

I’m using SDKBOX IAP version 2.3.17.9 plugin on Cocos2d-x 3.16 project. Here’s the issue:
After I call sdkbox::IAP::purchase(“product_id”) there is a long timeout: 30-60sec. After that either I see a message that I can not connect to iTunes Store, or I see purchase confirmation alert and after confirmation there is also long timeout with an error in the end.

NOTES:

— Network is fine

— productRequestSuccessCallback is called with correct product

— I tried to enable/disable In-App Purchase project capability and it does not help

— The In-App Purchase in “Waiting for review” state right now.

— I did not find out how to whitelist canOpenUrl function since it requires to provide a schemes in LSApplicationQueriesSchemes and there is no word about scheme on SDKBOX documentation

— Here’s code:

AppDelegate.cpp:

#include “IAPManager.h”
#include “PluginGoogleAnalytics/PluginGoogleAnalytics.h”
#include “PluginReview/PluginReview.h”
#include “AppDelegate.h”

…

bool AppDelegate::applicationDidFinishLaunching() {
    …
    sdkbox::PluginGoogleAnalytics::init();
    sdkbox::PluginReview::init();

    sdkbox::IAP::setDebug(true);
    IAPManager::getInstance();
    sdkbox::IAP::init();

    return true;
}
…

IAPManager.cpp:

#include <math.h>
#include "IAPManager.h"
#include "ProgressTracker.h"

USING_NS_CC;

IAPManager* IAPManager::_instance = nullptr;

IAPManager::IAPManager() {}

IAPManager* IAPManager::getInstance() {
    if (IAPManager::_instance == nullptr) {
        CCLOG("creating listener");
        IAPManager::_instance = new IAPManager();
        sdkbox::IAP::setListener(IAPManager::_instance);
    }
    return IAPManager::_instance;
}

IAPManager::~IAPManager() {
    sdkbox::IAP::removeListener();
}

void IAPManager::onInitialized(bool ok) {
    CCLOG("initialized %d", ok);
}

void IAPManager::onSuccess(sdkbox::Product const& p) {
    CCLOG("success");
}

void IAPManager::onFailure(sdkbox::Product const& p, const std::string &msg) {
    CCLOG("failure %s", msg.c_str());
}

void IAPManager::onCanceled(sdkbox::Product const& p) {
    CCLOG("canceled");
}

void IAPManager::onRestored(sdkbox::Product const& p) {
    CCLOG("restored");
}

void IAPManager::onProductRequestSuccess(std::vector<sdkbox::Product> const &products) {
    auto product = products[0];
    CCLOG("products request success %s", product.id.c_str());
}

void IAPManager::onProductRequestFailure(const std::string &msg) {
    CCLOG("product request failuer%s", msg.c_str());
}

void IAPManager::onRestoreComplete(bool ok, const std::string &msg) {
    CCLOG("restore complete %d %s", ok,  msg.c_str());
}

It’s been going on for 3 days already. Did they (Apple) report any problems?