Check the assignment
A created task goes to the person or staff group set on the rule's action. If it went to a group, make sure the right people are members of that group under Team > Groups.
Check the task list
Even without a push notification, the task appears in the assist app task list for the assigned staff. Ask them to open Tasks and pull to refresh.
Push notifications
Push alerts need notifications enabled for the Paddl app on the person's device. If they turned notifications off, they will still see the task in the app but will not get a push. Notifications to managers appear in the in-app notifications list.