Due to security concerns I have turned off user visibility. My understanding wa

I believe that is where the problem will pop up. Impact in various areas of Appian with regard to user visibility from documentation you may have already reviewed:

forum.appian.com/.../User_Profile_Visibility.html

Within that documentation, is Impact on Search:

Impact on Search
If a user is not visible, the user does not show up in any search results, including the People Picker. As discussed earlier, the user can still be found through group membership lists, but only the username appears.

Also, impact upon users/groups:

User Lists
If a user is not visible, the user will not show up in generic user lists, such as the Users record list in Tempo or the initial list displayed when accessing the People tab. He or she will, however, still display in the membership list of any groups the user is a part of. In this case, only the user's username displays.

Besides the user visibility setting, the user's role map, which determines the specific visibility of a user to a set of other users.

I'd review the documentation there pretty carefully, and see if you can find anything useful to incorporate on your side to try and get the desired results.

I believe that is where the problem will pop up. Impact in various areas of Appian with regard to user visibility from documentation you may have already reviewed:

forum.appian.com/.../User_Profile_Visibility.html

Within that documentation, is Impact on Search:

Impact on Search
If a user is not visible, the user does not show up in any search results, including the People Picker. As discussed earlier, the user can still be found through group membership lists, but only the username appears.

Also, impact upon users/groups:

User Lists
If a user is not visible, the user will not show up in generic user lists, such as the Users record list in Tempo or the initial list displayed when accessing the People tab. He or she will, however, still display in the membership list of any groups the user is a part of. In this case, only the user's username displays.

Besides the user visibility setting, the user's role map, which determines the specific visibility of a user to a set of other users.

I'd review the documentation there pretty carefully, and see if you can find anything useful to incorporate on your side to try and get the desired results.