Null Receipt and Signature response with SDKBOX IAP on Android

Hello,
I’m using Cocos2d-x3.8 and the latest SDKBOX IAP for purchase subscriptions on android.
When purchase our subscriptions, Play store shows the finish purchasing overlay and I can purchase them.
But after this, onFailure event handler is called with the bellow error.

IAB returned null purchaseData or dataSignature (response: -1008:Unknown error), purchase: null

And sdkbox.IAP.restore() also returns emply response.

My sdkbox_config.json is like this.

{
    "android": {
        "iap": {
            "items": {
                “my_item1”: {
                    "type": "non_consumable",
                    "id": “my.subscription.item.1”
                },
                "my_item2”: {
                    "type": "non_consumable",
                    "id": "my.subscription.item.2”
                }
            },
            "key": “MY_KEY”
        }
    },
    "ios": {
        "iap": {
            "items": {
            }
        }
    }
}

Other SDKBOX’s event handlers work well.
And I tried to use sdkbox::IAP::enableUserSideVerification(true), but it doesn’t change anything.
Could anyone know how to get receipt and signature?
Thanks.

Maybe it is a network issue. Plz make sure here is only one request at the same time.

Thank you for your reply.
May I ask the detail of network issue you said?
I tested in different environment, office and my home network, but I’v gotten same result.

Is the purchase successful?

I updated .jar files, then I can get them.
Thanks!

Hello!
I had exactly the same error.
When you purchase NON_CONSUMABLE IAP, it is called onFailure
While buying CONSUMABLE is called onSuccess
The version of sdkbox-iap_v2.3.17.9.
I tried to replace all the files of the plugin did not help.

cocos2d-x-3.16
Created an empty project to integrate sdkbox-iap_v2.3.17.9
the error remained the same with the purchase of NON_CONSUMABLE
error: “IAB returned null purchaseData or dataSignature (response: -1008:Unknown error)”

sdkbox_config.json
“iap”: {
“items”: {
“test_item”: {
“id”: “com.item1”
},
“remove_ads”: {
“id”: “com.subscription.remove_ads”,
“type”:“non_consumable”
}
},
“key”: “MIIBI…”
}
any ideas?