Ever had this happen?

[Packlife]

Hey guys last night i was playin sum SH5, the first part of the campaign total Germany i belive hunting in the British Coastal waters tryna sink 50,000 tons of shipping any way i had received a report to patrol a new section farther north so not too long after i arrived in the area i ran into a merchant ship it was dark an raining but i was able to strike her w/ 1 torp n it looked like i broke her back then my flak gun crew opened up on her. Now heres the crazy part she wouldnt sink for nothing, my guys must of put 10 HE rounds all up an down her sides she was full ablaze listing horribly to 1 side an her front end is submerged and thats where she stayed, I even took control of the deck gun an sank rounds into her engine compartment an under her waterline an nothing, her symbol on the map dissapeered but it didnt replace it w/ the sunken ship symbol, we sat there an watched her n all she did was burn n stay in the same position. After like an hour we took off.
I did end up running into a large convoy early in the morning sunk 4 ships an barely escaped w/ our lives we caught them coming out of a port got in between them after sinking the 3rd or 4th ship her escorts started at our position, we dove as deep as we could but it was only 24 meters deep we were able to creep to a little deeper water the whole time hearing the escorts sirens going off as they went over us dropping depth charges but lucky for us they set'em too shallow so we just went on silent running an killed the engines an waited them out till it was safe enough to put it in slow ahead 1/3 an snuck off, heading home to complete the patrol an then CTD smh lol