There used to be a bug where lights would break all together if they were parented into a bone, were that bone was also a child of another bone, same story for attachments, luckily this got fixed!
However, I found a new problem, if you do parent a light like i described above, they will NOT update if you have them parented into a bone like this, which is animted, they will simply render from the WorldCFrame/CFrame and not consider the TransformedCFrame / TransformedWorldCFrame.
However, if you are previewing a animation inside of the animation editor with this setup, the lights will correctly render? Just during runtime this will not work. What is interesting is if you change .Enabled of the light it does properly re-render,I believe the issue stems from that lights dont consider TransformedCFrame/TransformedWorldCFrame changes as indicators to update the lights casting origin?
Here is the issue during runtime.
My System Info is:
NVIDIA RTX 4070
AMD Ryzen 7 7800X3D
32GB Memory
Roblox Studio running on DirectX 11.1
Expected behavior
The expected behavior like mentioned previously, is that lights should consider updates of Bones/Attachments inside animated skinned mesh rigs to properly update their casting origin.
Here is what i expect the behavior to be like in a video, inside the animation editor the behavior works as I expect it to.
(Dont get confused, the reason you can hear audio is because of a plugin that lets me preview post processing and other things in non-runtime!)