Search and merged tickets

We have a set of tickets where data has been merged instead of
replicated and duplicate tickets closed or deleted. Now I think we are
running into an issue.

When a ticket is merged, its subject and content lines are popped into
the stream of the new ticket. However, it appears that they are no
longer searchable. Whether attempting to search on subject or even
content, I haven’t been able to find a way to do this type of search
successfully.

Has anyone else seen this or have a workaround/fix?

Dallas

(running RT 3.8.6)