Torpedo prob
 

Sounds like a dud.

yea it was a pian in the ... for the skippers :) turn off duds in the difficulty screen

Need a little more info, What was the weather when you fired?

Rough Seas cause alot of premature detonations. If that is the case try setting torps to contact detonation, it seems to help.

If your getting that in calm seas, i would suspect a bug.

Its strange that it keeps switching back, Sorry i can't be more helpful.

Does anyone else have this issue or know how to fix it?

Somethings not right if you can't change the settings from influence to contact, maybe mod soup.

If you have them on influence it's normal for them to premature, but they are less likely to dud. If you set them on contact, they are less likely to premature, but more likely to dud...sort of a balance..

For a better chance against duds slower speeds seem to help as they don't contact the ship as hard and at more angle.

Conditions of the sea can effect prematures, so rougher seas better to contact until late 43.