Bug report: FBX to VRMA not working as expected?

[Benjythebee]

Describe the bug

I am trying to convert complex animations to VRMA since Blender won't export FBX properly.

I have this FBX boxing mixamo animation.

I tried exporting it as VRMA in Blender 4.2 (VRM Addon 2.20.88)

This is the output: https://github.com/Benjythebee/three-vrm-cache-repo/blob/master/cheering.vrma

but upon re-importing the VRMA into blender, the bone positions are completely off.

Do you have a way to make advanced animations work as VRMA?

To Reproduce

Load FBX boxing mixamo animation into Blender,
set the VRM and assign bones;
Here is a JSON of the mapping of the bones just in case:
mixamoVrmMap.json

Export VRMA, re-import in another Blender window or drag and drop VRMA in three-vrm-animation

Expected behavior

Bones should be the same position, and animation should work as intended

Desktop (please complete the following information)

• OS: Windows 11
• Blender 4.2.0
• Addon Version 2.20.88