I am a level one seller and The Gig which was ranked to the top three pages and having 45+ reviews and I don’t know why my gig is completely de-ranked and it’s now not showing in the search result. what is the reason behind this?
This was probably due to gig rotation. Fiverr is constantly rotating gigs around in the search results, so your gigs tend to move around a lot.
This post might also be a good explanation for you: GIG Ranking issue answer finally provided by the CS