Task List Internal/External Disappears When Associated w/ Milestone

Task List Internal/External Disappears When Associated w/ Milestone

I noticed that when a Task List is associated with a Milestone, a user can no longer set Internal or External visibility.  This may make sense if the Task List inherits the visibility of  the Milestone, but it turns out this is not the case.   

I had an internal Task List and associated it with an external milestone.  Unfortunately, none of the task list items showed up to the client account.  I was not able to subsequently edit the Internal/External visibility of the task list.

Depending on the desired behavior, the solution would be to:
  1. Inherit the visibility of the associated milestone   OR
  2. Allow the Task List visibility to remain editable 

The work around for me was to unassociate the task list with the Milestone, edit the visibility, and then reassociate the task list with the Milestone.