LockscreenVisibility is always -1000 after creating a notification channel

[thomasgalliker]

NotificationChannel.LockscreenVisbility uses the enum NotificationVisibility which has the values Secret=-1, Private=0 and Public=1. No matter what I do, when I create a new notification channel with one of the enum values, it alwass returns -1000 when I read the list of all existing notification channels. Does anyone know why this is?