Artifacts on uploadable models

On some models that I upload, some vertices are randomly shifted. It’s not a triangulation problem. If I open the same (uploaded to sketchfab) file in Marmoset Toolbag or another sofrware (reimport it in Blender or 3ds Max), this problem does not exist.
I usually upload .fbx, but I also tried collada - the result is the same. I create files from 3ds Max and Blender - the result is again similar.
I didn’t notice this problem on static meshes, only on skeleton meshes.
I use Firefox browser and Windows 10.

How to avoid the appearance of such artifacts?

I asked the same question a month ago. Here is the very good explanation I recieved:

I was successful in at least limiting the displacement of the vertices a lot by increasing the scale of my model, by scaling up the model 100 or 1000 times bigger or so.
I was unable to avoid the points of my UV-map becoming slightly compressed/displaced aslo though.

Hi. Thanks for the advice, but it doesn’t help. I’ve tried both -manually increasing/decreasing the parent bone and scaling while export - the result is still terrible at some points.