Not sure if this is a bug (and even if it is it’s rather minor), so I’m making this a suggestion instead. In the later releases, aside from the larger, slower clouds that cast mild shadows on the landscape, there are apparently denser and/or closer, smaller clouds (judging by the smaller but darker shadows they cast). This is fine in itself, but it looks rather strange when they move in different directions than the larger clouds, as they do. I suppose they could be at a different altitude and therefore caught by different wind currents, but, I don’t know, it just looks a bit off, to me.
See the video at, for example, 21:45.