Big Mackerel are a myth prove me wrong.
so i got the fish, took a long time to do, but after i got it. the challenge never popped. I'm going to assume the Xbox and PlayStation will have the same issue with the achievement.
Finished all the fishing quests, after going through the issue where fish don't spawn or disappear. got the sword fish. ran around with it for about an hour. still no challenge.
ok so i got everything fixed but the first box. its stuck bodies do nothing. and it spawns IN front of the jars. right by the door. its moved just enough i can get over it, but I cant have him walk past it, which I'm assuming is the issue.