"Could not retrieve the transaction summary" Error When Setting Up Reminders

We are having an intermittent issue with our REST API client. Normally, it posts the signing package create request in DRAFT status, posts the request to add reminders then posts a request to put the request into SENT status. On rare occasions, the add reminder request fails with 404 Not Found "Could not retrieve the transaction summary for transaction". So, the signing package gets stuck in DRAFT status. Example: Posting package create request to https://esignlive.us.bank-dns.com/api/packages HTTP Status=OK, HTTP Reason=OK, Content = {"id":"Tz2goJpAuVso4Bp8pA1pFiaaVZ4="} Posting reminder configuration request to https://esignlive.us.bank-dns.com/api/packages/Tz2goJpAuVso4Bp8pA1pFiaaVZ4=/reminders {"startInDaysDelay":10,"intervalInDays":1,"repetitionsCount":3,"packageId":"Tz2goJpAuVso4Bp8pA1pFiaaVZ4="} HTTP Status=NotFound, HTTP Reason=NotFound, Content = {"code":404,"message":"The specified package does not exist.","messageKey":"error.validation.packageDoesNotExist","name":"Resource Not Found","technical":"Could not retrieve the transaction summary for transaction uid: Tz2goJpAuVso4Bp8pA1pFiaaVZ4="} What could be causing this. Is there a workaround or fix? Thanks, Tony