Hi, these all look amazing, great work! So are they using the exact same skeleton as Mixamo? Just asking because then I could easily retarget them for Unreal.
Thanks! They are not rigged with Mixamo. But yeah, it's still a humanoid skeleton. In Unity I just use exported Mixamo animations on them. But if you need, you should be able to import models to Mixamo also.
Try different browser or do it multiple times in Mixamo, sometimes it acts strange with these low poly models. Worst case import the model to blender and export it other format or something, might help too. Idk, doesnt work for some people.