Currently, in prod environment, when the Editor uses Platform UI to create a new User inside a User Group, the User Group's sub-items list is not refreshed if it was previously empty. If it wasn't empty, it still shows wrong sub-items count (for example "viewing 2 out of 1 sub-items").
This issue doesn't seem to be happening on 2.0.

Steps to reproduce

1. Create a new eZ Platform 1.13 installation and launch it in prod environment.
2. In the Platform UI, go to "Admin Panel" -> "Users" -> "Editors". Confirm that Sub-items list is empty (if it isn't, you can create another User Group and use it instead of "Editors").
3. Create new User inside "Editors" User Group.
4. Go to "Admin Panel" -> "Users" -> "Editors" again. The Sub-items list will still be empty.