Vertex order - issue with coloring

Hi,
I could not find a similar issue, yet.
I am using a mesh for which I store submesh data in form of index groups. With draco compression I am using sequential ordering hoping to keep the amound and order of vertices, so that I can create those submeshes in runtime. However, draco compression still seems to reorder or reduce the amount of vertices. The picture shows a box that should be yellow and get clean blue outline without visible triangles. If I use an uncompressed non-draco file, I do not get any issues.

Is it even possible to keep the original order?