The Preview Merge tab of a Constituent merge process provides a preview of the constituent records to be merged. After making changes to this list, and then returning to it at a later time, the data list was refreshed and the previous changes undone.
A Duplicate constituent search process was run some time between editing the records on the Preview Merge tab and returning to it.
The Duplicate constituent search process is what populates the data list on the Preview Merge tab. This is run Prior to running a Constituent merge process to pull in the desired records. Any time the Duplicate constituent search process is run, it will refresh the data list on the Preview Merge tab.
Steps to Duplicate
Go to the Constituents function area
Select Constituent merge
On the Merge Processes tab, select a merge process
Select the Preview Merge tab
Observe the list of constituent records to be merged
Click the down chevron next to one of the records
Choose Delete match
Observe that this match is no longer on the list
Return to this list at a later time, and the deleted record has been re-populated