I started a new career in April of 42. This gave me time to make Coral Sea and (hopefully) Midway.
I began Patrol 1 in a Gato without radar. I ran through Coral Sea and experienced 9 duds and a miss on a Shokaku. I then continued on to my objective, which was off the east coast of China. There I attacked a small freighter and experienced 2 duds, 1 circular runner (which I avoided) and 2 misses. I had to sink with gunfire. I then went to Midway, refitted, and prepared for the IJN TF. It was 1 June and I saved. When I came back, all saves (I normally keep 5) were corrupted.
I start over. Redo Coral Sea. Result: 10 hits on a Shokaku - all duds. That's 22 hits, all duds, with one circular runner. This time, after I'm away from all IJN forces I save. I exit the game completely, then restore. No problem. Once again I go to the PZ. This time I encounter no ships. On the way to Midway I spot a Hakusika Maru in the early morning hours of 21 May. I save at that point. I pick up several hours later, no problem. I move into a position to attack and target with 6 torpedoes. Result: 6 duds. Now up to 28 duds. This is absurd. I save before going into the gun battle, then decide that I should rerun the attack to see if I get 6 duds again. I return to the menu without exiting the game and upon restore see that the date and time are right but now it is broad daylight. The ship is no longer visible and all of my marks on the map have disappeared. This is normally an indicator of a corrupted save. I let things run and then the passive sonar trace of the approaching ship shows up.
For the Dana Andrews career, I believe I went to the 2.1 patch of TMO. That career took place from 44 to 45. Even though it was later War and I had a dud-reducing torpedo expert, I got the odd dud with Mark 14's. It appears that the dud rate has been increased by some huge factor.
My plan now is to go back to an even earlier save and replay the Hakusika attack and see if I get 6 more duds. If it happens again, I'll either have to try to go back to the earlier TMO patch, which I know worked, or go forward to 2.2.
I logically assume all of this is TMO related since that is the only change I've made in my mods.