Hopefully someone here can help out with this, because everything I've been able to Google about this has come up with conflicting information.

I'm in the process of trimming down a bunch of my various collections, and in the process of moving some of my old G Gundam MFiA figures, the long "wings" on the back of the God Gundam just... well, shattered, basically. The soft plastic had solidified and gotten extremely brittle. It looks like that was the only one it happened to, as the others look good for now. Also, it ONLY happened to the white parts of the wings, as the red, middle pieces look fine. They were also heavily yellowed in comparison to the rest of the figure.

Does anyone know what might have caused this and, if so, what I can do to prevent it from happening in the future? I've seen some suggestions it's UV light and temperature, while others blame shoddy manufacturing, which is making me wonder if ALL of those figures are going to have issues down the line. If it's a purely soft plastic issue, I'm a little concerned about some of the Transformers figures who have similar parts.

The only other weird thing is I also just had an issue with an old Starrior who had the same problem, even though it was hard plastic, there was significant yellowing and it pretty much shattered. I figured that was due to age and cheap materials, but now I'm not so sure. They were both on display in the same room, though neither was near the window so wasn't subjected to any direct sunlight.

Any thoughts would be really helpful. Thanks!