Animals visually disappear, return after restart

When playing (as far as I can see, randomly) animals disappear visually, but they keep on making sounds. So basically I can hear my sheep and chickens but can't see them. I've tried everything but the only thing that helps is to actually restart the game. It seems to happen when I go away so I can't see them, and then come back (mostly when I'm away on a bit of a distance, like deep inside mines). I can still feed the animals and kill them, but can't see them until I restart.