I play multiplayer with a freind also - he hosts - and I reguarly have this happen, sometimes after a short while (10 mins maybe) and sometimes it's OK for an hour, before it happens.
Usually it's things I interact with that dissapear, like forges or trees, then it gets progressively worse, to when the entire ship is invisible, or I can only see the Hull, no ladder, masts etc.
Yesterday we were playing and landed at a new Yland, and the entire place was bare.
Logging...