Im looking at your TDC settings on the bottom right panel of the screen.
according to those settings, at the time you fire the shot you are apparently shooting at a target with the following TDC settings
Speed: 0 knots
Bearing 000 degrees
AOB 0 degrees
Range 500 meters
this tells me that your fish are leaving the tubes aiming at nothing but open sea as they do not have the programmed data necessary to know where to go in order to hit anything. Your fish are missing astern is my best guess... probably by at least a couple of boat lengths
EDIT: seeing that you are playing on 100% realism you will likely have to input all those parameters manually.
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