no kill credited?

[Dronston]

Originally Posted by Jimbuna

No credit for sinkings can be taken for granted until you receive the message "She's going down"

Obviously
But did you experience it before?
This was my first time in open (deep) water.
As was said before, it did happen to me when I raided harbours where water was shallow and the ship never sunk all the way (more often I did get credit, but ok).
So I'm wondering if this is a bug or maybe caused by a mod or just bad luck?
Any how, I will reload the patrol and try to sink the same ship again and see what happens.