We are using SP2013 enterprise on-premise. On a site collection we have setup a content search webpart to show latest updated documents and pages.
Supposingly the webpart should show the title of pages and document (office word, excel, powerpoint). However, I found it is showing the first sentence of document instead.
After some investigation, I tested when I key in the "title" field when upload the document, CSWP will show this "title" properly.
However, for the old documents, whatever I do to update, the CSWP still show the 1st sentence. (I have tried key in the title field, delete the doc and upload again, update the content of document, etc) All the documents I tested (old or new) are resident in the same library.
What is the problem?