[SOLVED] DrawUserPrimitives culling parts of mesh with RasterizerState.CullNone

I am drawing hexagonal mesh divided into chunks using DrawUserPrimitives, each chunk has its own width and height. Each hexagon is drawn on different height, and this works as long as sides connecting different heights are not drawn. With sides drawn, half of each chunk is not drawn.

Relevant code: pastebin

As far as I know, no culling should occur because graphics.GraphicsDevice.RasterizerState = RasterizerState.CullNone;, yet it still does…

just hexagons, no sides:

with sides drawn:

I have also tried using graphics.GraphicsDevice.DepthStencilState = DepthStencilState.None;, with same results.

Shader used is just empty shader for testing purposes, I have also tried this with BaiscEffect, with same results.

Also if Vertices list is reversed, then the offset of parts of chunks not drawn is changed.

I would highly appreciate help, I am stuck at this for a whole day now, Thanks!

As it appears, I got the number of primitives wrong. Works with updated number of primitives.