Summary
Whenever aiming at an enemy, from both land and raft, the sensitivity becomes extremely jumpy. So far anything that can be aimed is affected, spears, speargun, bow, etc. with the speargun somehow particularly bad. When moving the mouse even slightly, the aim jumps nearly half way around the player, only in the direction moved but much more significantly than it should. After a bit this problem catches itself but then reemerges. Stopping the aim will return the sensitivity to how it is supposed to be, however sometimes it takes a bit of time, i.e. bad sensitivity for a couple of seconds after stopping to aim.
This happens in so far all games, single and multiplayer, at any time when aiming at an enemy and has been happening for a few versions now as far as I remember.
Settings
Nothing custom and playing around with sensitivity and smoothness settings does not seem to affect this issue at all.
Steps
Occurs everytime for me, I do not know if and how this can be reproduced elsewhere.
Extras
Reloading or reinstalling does not seem to fix this issue. I can record video footage if required. The normal gameplay is fine, fighting sharks and hogs is doable but must be done with great care and not moving while aiming. Fighting bosses is extremely difficult with this as you loose all orientation whenever you aim.