Strange, I'm in January 40, found a convoy and only managed to sink a ship and damage another before I was driven off by the escorts. 3 of 4 headed my way full speed. It was a night attack and they even fired star shells, it was like daylight and I had to crash dive. Then 2 of them dropped DCs around me for four hours before they finally gave up. I can't believe they were that good in Jan-40.
But, someting I noticed, if SH5 acts strange in one way or another, save and reload...and everything is just fine