Hi Martin,
This is an intended behavior. When user is restricted by taxonomies (for example: 2, 3) he can edit post only with those taxonomies: 2, 3. WordPress creates a new post in 2 steps: 1) inserts new post; 2) reopens it for editing.
If new created post will not have one of allowed taxonomies user will receive access error. Remember he is allowed to post new and edit existing posts only inside the list of allowed taxonomies. This is a reason why URE automatically assigns to a new created post the 1st taxonomy from the list of taxonomies allowed for this user.
User should check what taxonomy is assigned to his post and reassign another one.
If you have another issue please share the images to give me more details.
