As of today, November 17, 2018, any post with links, any links, even to other tumblr posts, just don’t show up anymore in tumblr’s search engine.
I just found out about it, after I posted a fic with a link to my masterlist and it got little to no notes (it shuldn’t). I was right – the moment I deleted the links, my post magically appeared in the search again. Wow.
Please spread the word to warn the others.
Dammit, @staff! Come on! Not all of us use links for evil.
Crowfanity's Tumblr 