I think that is due to the way it loots and where the fish is caught. If you have the sky in view it does not seem to do this, part water part sky in screen. Basically the loot screen forces focus higher and higher until you loose the water. With the water not taking up the entire screen less change of it forcing view up. From what I can tell.
Took me a while to figure out; why I would swim into the depths and die. Some times it misses the fish/bobber and if you have click to move you end up in the water. FYI turn of that feature.
I sat there and watched this bot for some time. Very nice work. Profiles work wonders too.