May be during this process anomaly occured and marking entry voided failed.

If this happens regularly then this needs to be debug in depth.

bank_account_reconcile did NOT list the items, so I searched the GL Enquiry for transactions in case they were registered against wrong GLs.

gl_account_inquiry listed these items with the non zero values (the values I was expecting - but with extra lines)

gl_trans_view.php opened the items, displayed looking like a Journal Entry rather than the normal Payment/Deposit pop ups.

gl_journal.php?ModifyGL=yes opened into the Bank Deposit or Bank Payment editored, but all lines were of zero value, and the date was today's date.  Altering and saving resulted in the next screen saying transaction 0 was updated.

I am currently on 2.4.19 but was on 2.4.1 until a month or so ago, so this data corruption could be from a while ago.

PROPOSAL:
1) A report that cross references the various tables that store this data and reports mis-matches.
2) an editor to clean these up - either a "force" for void or similar zero everything.  I haven't worked through this yet as EOY tax reporting is less than a week away.