Sage 50 Accounts ODBC query - transactions missing from audit split table

I have a long standing (5 yrs plus) excel workbook which is an extract from the audit split table for a client via MSQuery/ODBC.  The client is on V26.  

I noticed for the first time this morning that there is a large number of transactions missing from the table - they all seem to be journals created via the bank transfer screen.  

Has anyone else observed this or can anyone explain it?  I have checked a similar audit trail for a different client (v25) and bank transfers are all present.

The issue seems to start just after the last year end was run.  Could it be connected to the "No Bank Reconciliation" flag on the the relevant bank record?

Thanks