Error after GetProduct IAP on my app

I'm finding some issues with my iOS application that are related to the WebKit framework. I'm receiving the following errors in the application log:

01:05.995.258 Error Space Warhog (2434) com.apple.WebKit IPC 0x114088220 - Connection::dispatchIncomingMessages: IPC throttling was triggered (has 2'458 pending incoming messages, will only process 60 before yielding)
01:05.995.286 Error Space Warhog (2434) com.apple.WebKit IPC 0x114088220 - Connection::dispatchIncomingMessages: first IPC message in queue is WebUserContentControllerProxy_DidPostMessage

It happens just when I make a purchase in the app. It does the whole process correctly (apparently), but once the "Purchase successful" pop up appears, the result is duplicated. If I make a second purchase, once I get the correct coins, the APP freezes and I have to restart it.

Thank you for your help!