I thought this was going to be a minor bug, but maybe not. 2 things I've noticed concerning terraforming.

1) Terraforming ships will not accept move orders while orbiting a planet. Does not matter wether it is terraforming or not. I have to first tell it to go to an empty hex near the sun. Then issue move orders to another planet from that point.

2) Terraforming animation persists when I move the terra former away from that planet before full terraforming is complete. One time it only persisted until my next log in to the server. The most recent persisted through several log ins and through the night. It only stopped when I was trying to gather info for this post and appears it may have caused a minor server problem? I lost connection and server dropped from my list. I had to attempt logging back in a few times. although the animation persisted, the actual terraforming did not. The planetary value never increased above the 80% that it was when I moved the terra former
Info
Game Nisaha
Galaxy 0,1
Sector 5,6
Planet 614 persistent animation
Planet 612 where terra former is now

Don't know if this helps or not since the animation has stopped. But maybe you can verify if anything happened at approx 10:10am mst USA

Sorry. This should be in the tech support forum but I think I have messed that up