Wierd/Wrong import of COLLADA (.dae ) files

Hello,
I am currently using the [UnityMeshImporter project](https://github.com/eastskykang/UnityMeshImporter) which basically wraps [assimp-net](https://github.com/assimp/assimp-net) for Unity, to import at runtime a COLLADA file, but for some reason, the import seems to be all messed up.
I've tried using the Unity editor to import del file, here is the exptected result:

Yet, when I use the importer at runtime, this is the result:

Wierdly enough, some other .dae files get imported correctly, for example the anymal_thigh_r.dae attached to this issue get imported correctly.

I've tried different extension of the same file, for example .obj and .ply, which seems work to but I cannot get the vertex colors rendered in that case (feature I need)

Attached to this issue there is also the file used in the screenshot. As I am quite new to working with 3D files, I have very little clue on what might be issue.

Here are the meshes that causes the wierd behaviour:
[meshes.zip](https://github.com/eastskykang/UnityMeshImporter/files/5434351/meshes.zip)

Thanks in advance

Start by reproducing the runtime import in the UnityMeshImporter project with the problematic meshes.zip files, then compare the result with Unity's editor import and the correctly handled anymal_thigh_r.dae file. Trace the assimp-net COLLADA import path and determine what differs for these meshes. Done means the affected .dae files import with the expected geometry and vertex colors at runtime.

Written by the indexing model from the issue text.