jsonParse error with some rigged models

[polytropoi]

Describe the bug jsonParse error on certain models with skinned meshes

Files Attach or link to .gltf/.glb files that trigger the bug. https://ztash.s3.amazonaws.com/xbot1c.glb example of file that fails to parse, but passes validation

To Reproduce https://realitymangler.com/uxr/main/index.html?scene=AWHQ_2023_error see console

Expected behavior https://servicemedia.net/webxr/ObzaRcDuB aframe version of the same scene, rigged model works fine https://realitymangler.com/uxr/main/index.html unity webgl version with different model, no error

Desktop (please complete the following information):

• glTFast version 5.0
• Unity Editor version: 2021.3.18]
• Render Pipeline and version: builtin
• Platform: WebGL

additionally (if significant for the bug): happens in both editor and build.
Additional context I think all the models that trigger this error have Mixamo-generated rigs...