I followed the instructions here to add a new property in advanced search, and to be able to search based on the custom column I made (which are metadata tags).
It worked well last week; but this week I started editing existing documents within the same library to add their metadata tags. When searching, however, the content with new tags don't appear - just the old ones which appeared last time. This is even when I added the same tags to other files in the library. For instance, file A with metadata tag (in the custom column) 'Documents' appear in the search results, but file B with the exact same tag, but added only now, does not appear.
I have tried full crawling 3 times, as well as re-mapping the managed property to the crawled property.