It only updates its position when the model extents do, and the model extents sometimes dont update for a long time.
Happens both in studio and online.
Im using billboardgui on a moving object, usually it works fine but sometimes it jitters or stops moving for a long time. In studio you can see that the model selection box itself has the same behavior (it just doesnt update every frame).
Ill use a basepart instead of a model, which will probably avoid this bug.
Wait, you’re setting the Adornee to a model?
Yes.
The bug seems to be that model extents dont update every frame (its inconsistent).
I remember experiencing the same issue with selectionbox around a model (as I said it will also happen with the default studio selectionbox). So its not only billboardguis (if theyre only supposed to be used with baseparts). The instance I remember was that there was some thing floating in water (dont remember if roblox or custom water), and I had selectionbox on it, but the box didnt move smoothly with the object when it was pushed in the water.
In this specific case, the gui is adorned to a model that moves around.
The issue seems to take place when the object is moving linearly and not doing much (it uses bodyvelocity). When it starts rotating or movings its animated parts (scripted Motor6D), stuff starts updating frequently again.