Hi,
I think there is an issue with the modified state after changing some property in the editor.
Here is an example: https://plnkr.co/edit/C304jfwJ8X1HP6RyNQbG?p=preview
I have added the property notVisibleForGroups to questions. If I add a group, the modified state changes as expected. But if I add another group after the array already exists, the modified state does not change. So in my case, using autosave, the survey is not saved after that action.
Thanks!