When parent post is modified, child post slugs are reset to default

Using WordPress 3.8.1 and Types 1.5.4

I have a parent CPT created called Realtor, and a child CPT called Listing. I am using the "Post name" permalinks setting. I create a Realtor post and save it. I then create a Listing post, save it, and attach it to the realtor Parent post. I update the Listing slug to a specialized format (removing all hyphens). It works fine.

However, if the Parent Realtor post is updated, all the child Listings attached to the Realtor parent are automatically reset to the default slugs in their permalinks.