A particular issue on the Android network layer makes the default browser send two times the same POST request in response to a single request from the application layer (the javascript code).
We've seen this issue appearing randomly and only on SSL connections.

When this happens the first response is completely ignored while the second one is took under consideration.

As a result of this duplication the server reacts closing the session with an error 39 notified through the onServerError callback

A workaround is included in the next version of our library (a preview is available), in the meantime you may want to handle such error 39 on android browser opening a new session.