Are there conditions to export glTF format correctly?

I drew a threshold and contour data from 3D data (Structured (Curvilinear) Grid), and I exported scene to glTF format on Paraview 5.8.0. I checked it with 3D Viewer on Windows 10, but the shape was obviously different from Render View on ParaView. The shape of a triangular polygon with a only some part of the shape were displayed.

The shepe of the Example Visualizations that exported to glTF file was displayed correctly and same as Render View on ParaView.

Are there conditions that number of polygons or other conditions to export glTF format correctly?

I plotted threshold geometry
Type: Unstructured Grid
Number of Cells: 26311
Number of Points: 53647
Memory 2.7MB

Can you share your .vtu and .gltf file ?

The two geometries are the same here.

Are Paraview and Microsoft 3D Viewer the same shape in your environment?
Does the exported glFT format from ParaView not guarantee the shape on different software?

Microsoft 3D Viewer

gltf online viewer also give something similar.

A bug in the microsoft 3D viewer ?
Can you share what you have in the microsoft 3D viewer ?

Thank you for your kind support.

Mirosoft 3D Viewer screen shot

I reproduce the issue with 3D viewer. Since it is only failing there, it looks like a bug on their side. No idea of the reason why though.