I am not sure if this is the same thing sagsave has, but on my server I am exploring via TP with rcon and I went far...... out, to the taiga biomes actually and the trees twitch??? I thought maybe the map needed to settle in and build itself. Waited an hour, no. Went to work came back still twitching and Red knows with my special eyes
I get sick, then a migraine....
When moving too far away from the origin you will encounter visual glitches. They're caused by precision errors, unfortunately the world is not infinite yet. Though there is no limitation in world generation (so the world will always be generated, irrespective of your position), you run into these precision errors which make the game unplayable at a certain point (you'll notice minor glitches when being ~10,000 units away from origin, and the game basically becomes unplayable at ~100,000).
These "issues" will be fixed once the "infinite world" is implemented^^