I have found a possible bug in the GLB exporter.
The issue is that the exported GLB model gets messed up if it has a parent transform node and contains a skeleton.
Here is a PG of a model with get messed up when it is exported:
If the parent transform node is removed the model is exported just fine.
I have put the exported model on our CDN for illustrating the issue in this PG:
cc @bghgary in case he has a clue
There is a problem with the code that converts handedness. For now, you can set the scene to right-handed and then it will export properly.
PG: https://playground.babylonjs.com/#J4ZV2L#3
If you don’t mind, please file a GitHub issue for this. Thanks.
I have filed an issue. Thanks
Does the workaround work btw?
Yes I can confirm it works 
Do you know an simple way to convert a transform node from left to right?
The easiest thing to do is invert one of the scale axes.
This issue is now fixed in this PR: Stop baking LH to RH in glTF serializer by bghgary · Pull Request #13909 · BabylonJS/Babylon.js · GitHub.
Note that it’s a breaking change in the sense that we are no longer baking the handedness conversion, so be aware that the asset will be slightly different when exporting LH data to a glTF.