Thanks for the insight... I had a look at that file but I don't understand it
b) the submarine dives uncontrollably (when stationary undrwater) until it exceeds maximum depth and is destroyed.
I've not seen it happening while stationary. But diving Ohio at high speed, the sub is unable to get into the desired depth and tend to go further down... I guess that is because its displacement.
Same happen if in high speed (full/flank) lets say if the sub is at 350ft then issue a periscope depth... it does surface entirely 1 or 2 times until it stabilizes at periscope depth.