Drupal core search doesn't re-index the site and it always shows this message.

0% of the site has been indexed. There are 453 items left to index.

What settings do I need to change to make Drupal re-index the site properly?


You need to run cron. Because building the search engine can take time, Drupal does it on cron runs (the scheduling system).

First, to make sure everything is OK, run cron manually from /admin/config/system/cron to ensure that the search items get indexed.

Then set up cron to run automatically following the instructions in the documentation.