In Songspace, you have always been able to enter your grouping information in the Playlist Contact Information field of your Account Settings. But recently you may have noticed that this information is no longer appearing in the grouping field in iTunes. No need to worry - the information is still being sent.
This information now appears in the work name field in iTunes. Starting with iTunes version 12.5.2, iTunes changed how they handle the grouping field, which is why this change has occurred. Apple decided to remap grouping into the work name field of the new Work and Movement features designed to help with classical music.
That means that on the backend, iTunes no longer has a way to map to the grouping field. If you're woking on a version of 12.5.1 or lower, you will see the grouping field populated. If you update, you will see this information in the work name field instead.