I am working in SharePoint online. I just realized that for my list/librarie the search box is not working at all. I tryed redindexing the list: List Settings -> Advanced settings -> Reindex List - but without success. Also the reindexing of the whole site had no success. Some Ideas?
Does this issue occur on certain list/library or all the lists/libraries in that site collection? If the issue is influencing the whole site, Site Settings -> Search -> Search and Offline Availability, make sure the site is allowed to appear in search results.
And for certain list, you can go list settings>Advanced settings>Allow items from this list to appear in search results.