rest/api/search returns odd page title

Issue Summary

While firing the search REST API call such as rest/api/search?cql=title ~"test" to search for pages with the title "test". We will see the page title displaying oddly such as @@@hl@@@test@@@endhl@@@

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Log into Confluence
2. Make sure Confluence has page with the page title "Test" (or similar)
3. Run the following REST API call in the browser <confluence-url>/rest/api/search?cql=title ~"test"
4. Observe the JSON output returned from the call

Expected Results

JSON output displays the page title correctly.

Actual Results

JSON output displays the page title as @@@hl@@@test@@@endhl@@@ instead of just test

Workaround

The title of the page will still be rendered correctly in the "content" block.