Hi,
there is a fun interaction between the artifact that let's you teleport a fleet and the siege mechanic (:
so the steps are:
1. get a charge of the artifact that lets you teleport any fleet
2. wait for some civ to lay siege on another civ's planet
3. teleport the fleet that is doing the siege
Expected result: the very clever player avoided a siege on a world (without going to war)
Actual result: the planet under siege remains in that condition indefinitely and who knows where the fleet went and if the AI is trying to bring it back... or even if it can control it - i have no idea how to check that...
Anyway - my suggestion is to just break the siege in such conditions or limit the use of the artifact power on non-enemy AI controlled fleets. It feels like this power was created in order to blink away from enemies (or blink enemies away) and not much testing went into behavior on fleets that are doing siege
All the best and thank you for the fishes (: