Scirè,
Thanks for the feedback.
My mod only modify the departure's harbours. So, this is a SH3 default Campaign_SCR bug. By the way, I intend to do a deep rework on enemy ports soon ( perhaps for the next release).
Edit***: in the next release I will add some new uboats. But different harbours have different traffic, so, already exist some uboat at subpen or side by side in somewhere in the traffic mod.
Rubini.