In a previous project I needed to create separate USDZ files for each animation - one animation per USDZ file. I loaded the first USDZ model and kept both the model and animation. For additional animations I loaded the USDZ file, kept the animation, and dumped the model part. I could then apply the animations to the full model I loaded first.

I figured out one way to do it from Apple's source code. I posted the solution here: https://developer.apple.com/forums/thread/724014

Figured it out! I needed to plug-in my phone and build for the actual device (as opposed to the simulator) Building for Any iOS Device (arm64) works too.

Looks like the optimal lensPosition changes over time. Could temperature change from device usage and ambient temperature changes affect the optimal lensPosition? If so, it looks like I will have to recalibrate lensPosition on a regular basis.

Success! In another thread someone mentioned installing older versions of Autodesk software, and that did the trick for me too. (Note: This is still with Monterey 12.2 not the 12.3 beta where I initially had problems) Here is the previous thread where I found the suggestion to try older versions of Autodesk software. https://developer.apple.com/forums/thread/661927