Setting SovrenClient.ShowFullRequestBodyInExceptions and then printing the SovrenException.RequestBody when an exception is thrown does not work. The SovrenException.RequestBody is simply an OkHttp Request object with .toString() called. That is not what is intended.
Instead, we need to serialize the actual body of the request in the getBodyIfDebug method. Here is an example of how to do that: StackOverflow