Cannot Create Tenant Admin

I seem to be unable to create a tenant level administrator.

When I enter a username and password in the Tenant Management screen and save my changes, the screen reloads without throwing an error. If I go back into the tenant or go to System Settings > Administrators, the new admin doesn't show up either place.

I can, however, create a system level admin.

I'm not sure what else to look at, so I'm not sure what other information to provide.

As always, any help is appreciated.