Greystripe plugin triggering ANR (timeout)

So here goes,
I'm currently porting Save Toshi DX to Android and I wanted to add Greystripe interstitial ads between the levels,
I've written a plugin to communicate with the greystripe API and it works great in my test project which consist of nothing but the ads. but when I put it to use in my game I have a problem that comes from the size of my game.

The ads runs fine when I call them from the game but when I dismiss the ads. the SKIP button becomes unresponsive, then it takes a few seconds to close the ad, and then another few seconds to reload the game. during this time sometimes I trigger ANR
I load the ads from an empty scene and make sure there are no large assets loaded.

From the greystripe wiki I got this info on the issue:

Anyone has any idea on how to solve the lag and the ANR ?
Thanks!