I just completed my first patrol and sank 2 merchant ships. One britain and one sweden. But after I sank the one from sweden I found out they weren't listed as an ally until 1940. I sank them in 1939. I still got credit for the tonnage. On the way into port (at 1024X speed) I also ran into a german patrol boat
who promptly started shooting at me. I exited the game and hit return to port. I assume I lost renown for either of these or both. I am playing with GWX 3.0.