Hmm, i just take a short look, not sure if anybode reportet it , saw only animals run trough solid objects ^^ ....just in case...

Animals get frequently stuck at Rivers. Specially bears. They just sit at the shore of a river and dont move, run or else. Only if a enemy comes close they beginn to run. Looks like big black furry rocks sitting at the shores

Strangely, if they get attack, they can swim trough the river, but without provocation the bears seems simply to hold position there. And not to move...(i waited over 30 mins for a bear to move from there, nothin happend)