Hi @Deltakosh, I have this issue too, with babylon v4 as well. The error happens 50% of the time, likely some kind of race condition.
Specifically, this code in my whole set causes it:
var hl = new BABYLON.HighlightLayer("hl1", scene);
hl.addMesh(itwData.spheres.earth["sphere"], new BABYLON.Color3(0, 0, 0.5));
hl.addMesh(itwData.spheres.earth["sphere"], new BABYLON.Color3(0.5, 0.5, 1), true);
This is adding a color as/to a mesh, not based on a size anywhere.
Let me know if you need to see this.