It is probably because you have not been attached to the new committee. Contact your administrator to get access to the new committee.
COMMITTEES AND DMS INTEGRATION
Important: In the committees with integration in Prepare, new committees are automatically created as soon as you have published for the new committee in your document management system. You should therefore not create a new committee in Prepare. You must therefore remember to be added to the committee and get the rights as the agenda producer, to be able to publish agendas in the new committee. As soon as you have the rights as the agenda producer, you will be able to see the new committee under "Import" in Prepare.