Uploaded a bunch of htm files to a Sharepoint Server 2013 (on prem) library. Crawled the contents, confirmed in the log. I'm able to search the contents of it successfully.
Did the same to a library in Sharepoint Online. Even after a while I can't get the results of search from that content. Can't check the crawl logs so I'm not sure if Sharepoint Online is actually being able to crawl htm's contents.
At first I thought the files had some no-crawl header tag of sorts, but it did worked fine on on-prem crawl. Why would Sharepoint Online ignore it's contents?
Similar question here: