Eclipse SUMO is an open source, highly portable, microscopic and continuous traffic simulation package designed to handle large networks. It allows for intermodal simulation including pedestrians and comes with a large set of tools for scenario creation.
Please provide example inputs for reproducing this issue. You may also send the .xodr privately to namdre.sumo@gmail.com.
What version of netconvert did you use?
you can notice the weird conversion of sumo as opposed to the open drive. sumo is deleting roads for example road 210, 209. and place nothing instead.