Users are receiving notifications to receive things they have already created receipts for

Summary

Users are receiving duplicate notifications to receive things that they had already created receipts for in My Receipts.

Content

Our users are receiving notifications to complete Receipt Confirmations for POs that they had already received on in My Receipts. They are also experiencing that their notification are not clearing once the receipts have been received. 

Has anyone experienced this before?  Is there a way that we can make it so that once they receive on the PO, they do not get alerts to receive again for the same one?