Missing Group Control records prevents unposting

I have a user who processed a deposit with 14 payments two of the payments came from single check from their customer so I'm focused on the two payments.  They need to unpost the payments. They were able to unpost one of the payments, but not the other.  When I look at the data, it seems as if the group control record is missing.  This shows the results of a query showing the items related to these two payments

In this query I started with the ITEM_ACTIVITY table and joined (left outer) to the GROUP_CONTROL table.  It looks to me as if the Group Control record for the Group 12233 (at the bottom) is simply not there.  Any ideas about what I might be missing? What might have happened? How to fix it?  Thanks in advance!