Why can't I get a straight running solution anymore?
 

I can't get a straight up "fire on this bearing" after having a previous solution. The torpedo line always stays in the same place even after I turn off TDC tracking, set speed to 0, AoB to 0. None of it resets the torpedo run on the attack screen.

Any ideas?

Did you shut off the TDC? I believe it is a point and shoot with the red button off.

Yes, I shut off the TDC and the attack map still shows a torpedo run on the last solution. I'm wondering if the attack map lines are just incorrect in that case.

Try inputing range with the TDC. That usually updates the TDC, so maybe it needs a range input to recognize that TDC is actually off.

....just guessing but worth a try.

In US Submarines, the bearing was sent on "mark". You need to send range and bearing together to set the direction for firing.