IAP signature verification failed

[wolution]

I am implementing In app purchase for android, following exactly the steps described here:
https://software.intel.com/en-us/html5/ ... -intel-xdk

After publishing in the in the play store as alpha version, I was able to successfully initialize the plugin, and buy one of my test products. Since this worked out correctly (I received the bill via email from google), the RSA key used in the init function is clearly correct.

However directly after the purchase, and since then every time I call the init function, I get the following error:

ERROR: Error purchasing: labResult: Signature verification failed for sku test1_purchase (response: -1003: Purchase signature verification failed)

Any ideas how to resolve this?

Thanks!