Assume that there are two users, user A and user B. At first, user A signs in Microsoft Skype for Business 2016 in a Citrix environment. Then user B signs in the client in a normal environment. In this situation, if user A sets the custom location, user B cannot see it. Then, if user A disconnects the Citrix Xendesktop (The client is still running on VM), user B can see the custom location.
This issue occurs because when you determine whether the location should be published, you only check whether the user is in VD1v1 or not.