Dear @Alex T⚜️ ,after update to 13RC3:

Assignee gets saved now.

Unfortunately, assignee doesn't show up in the Assignments field. Additionally, once assigned, I cannot delete assignees anymore. If I delete one or more and save, the assigned members are still in the assignee list of the form.

Tasks list in container element (here events) doesn't get updated neither.

Edit: Notifications work for the assignments.