Access to BPM data lost with application of 18C

Summary

After applying 18C to our Production environment, some users are no longer able to see Payables Invoices.

Content

Was there a change to any Payables Security Roles in 18C that would have impacted a user's ability to see Payables Invoice transactions in the BPM?  Prior to 18C these users were able to see all transactions - requisitions and Payables Invoices in the Administrative section of the BPM.  After application of 18C in December, these same users no longer have Invoices appearing in their view. 

I appreciate any input on what might have caused this change. 

Judy