Notifications are affected depending upon how you choose to acknowledge items. There are two basic scenarios when resolving items:
One item exists in a threshold and you acknowledge or resolve that item. The corresponding notification is also deleted and no more notifications for the item are sent.
Several items fall out of threshold at the same time and one notification is sent for the group of items. If you acknowledge or resolve only one item, a corresponding notification persists for all other unacknowledged and unresolved items.
However, if you select one item from the group, acknowledge or resolve it, and then select Apply to any items created at the same time as this item, the corresponding notification stops for all items that were created at the same time as the selected item.