The 'test battle' screen has been there for quite some time, not recently. Also, while I understand your good intentions, it is almost impossible to not get banned by using the mod, it is only a matter of time. Thus, I recommend playing a legit account, and just using the mod for testing builds...
I suspect that the disconnection during GR and WB flags Vespa's mod detection system. Also, even though the mod apparently has no effect during PvP and DR, it is possible that using it during those instances will trigger a flag.
This is why I said that it is best not to use any mod during those...