This is the mod by LGN1:
https://www.mediafire.com/file/ejqku...rm_Mod.7z/file
You may be able to get some insight on what is going on.
This a copy of the readme :
Torpedo Alarm Mod Readme
LGN1
January 2018
This mod solves a problem which has annoyed me for many years: the missing reaction of ships to premature torpedo explosions (when you attack a ship and the torpedo prematurely explodes the ship/convoy just continues as if nothing has happened). I think this is higly unrealistic.
This mod causes ships to react as being hit when a torpedo explodes within the range of 1000m.
Known issues: There are no damage textures to a ship's hull when a torpedo hits it. Unfortunately, I was not able to fix this. However, for players who do not use the external camera, this should hardly matter.
Best, LGN1