Wierd problem with drawing mesh, never faced before

I made quite many remeshing tool in Rhino 5. Recently making new remeshing tools in Rhino 6.

They are working perfect. Just some times it create mesh , which I see as mesh display conduit view. But when I draw the mesh by a button click, it does not draw a mesh in rhino view port.
It never happened before. Just very rare case, still I am curious why certain meshes are visible in display conduit, but not drawable in viewport.

Normally, when a mesh is visible in display conduit, it is a valid mesh, and 100 percent of the time, you can draw the mesh in view port.

What could be the reason, mesh is not created, even though I can see clean mesh in Display conduit.

There is no way we can answer this without seeing (and perhaps running) code that repeat the problem.

– Dale