Question about torpedo ignoring target

[letterboy1]

Hi all,
I play on full auto crew and have an issue that is most likely operator (me) error. I am playing a mission called "First Strike" from a compilation by Miika. In it there is an Iranian frigate which is hard to identify and often shows up as a torpedo, but eventually I make visual confirmation with the periscope. I then fire by using the map and right-clicking on the frigate's icon choosing "Engage With." I've tried TASMs, Mk-48s, and Harpoons and every time my target is ignored. I've had torpedos pass within feet while active and not pick up on the frigate. The missiles don't even start off in the right direction and go nowhere.

Obviously I made the mistake of thinking that auto crew takes care of all the TMA and fire control stuff. I've had success with it this way, but my repeated failure in this mission tells me that I messed up somewhere and will likely do so again when faced with a similar situation. Why would an active torpedo go right past a frigate within feet? I will open my manual again and see what I am doing wrong but would appreciate any tips to point me in the right direction. Thanks.