Hello,
We discovered that a bunch of our old animated models were no longer animated on iOS15 and onwards. After a few days of playing spot the difference between usda files I noticed that all the broken models had an xform called "Scene". Lo and behold, changing the name of that xform fixed the issue on all the models. Even lowercase "scene" makes the animations work again. Is "Scene" a reserved keyword or something? What other keywords do we need to avoid so we can create more robust USDZ files?
I'm surprised this issue isn't more widespread considering Blender wraps models in a "Scene" node.
At the drive link below you can find two animated cube USDZs. The only difference is the name of one of the xforms. The one with a "Scene" xform is not animated in quicklook (replicated on iPhone 13 iOS v15.2, iPhone 13 iOS v 18.3, and various devices on Browserstack including iPhone 16 iOS v18.3).
https://drive.google.com/drive/folders/1dch1WaM9O6mbHy29S6NGWgnSHkZkPiBf?usp=sharing