This is a very weird behavior and i was able to test it on other peoples playgrounds… example
i also tried different loaders and they all basically are the same, either the scale.z is set to -1 while x and y are 1;
and/or the rotation.y gets set to 180
drag and dropping in the babylon editor of a gltf/glb does the same. I also tried different versions of babylon and the results were the same.
all of this is on the root node.
This does not happen in ThreeJS, the root node’s scale are all set to 1, and rotations are all set to 0.