It might be because the average gig rating for that gig went down. Check reviews to see what you could improve on such as communication or whatever.
In one review reply you say “you prefer huge revision…” but you’ve put unlimited revisions in the basic package. If you don’t want to do too many revisions, you could change it so that none of the packages have unlimited revisions. Also normally the higher priced packages would have more free revisions than the lower priced ones but you’ve put unlimited revisions on the first 2 packages. Also your premium package is called “silver” and your standard package is called “golden” - normally gold is higher than silver.
So to improve the rank, maybe work on any things said by buyers in their reviews that they thought could be improved on or that they didn’t rate highest for (eg. see rating breakdown section where it gives seperate score averages for communication, recommend, service as described). If you take any points given by buyers into account when doing your next orders maybe the review average could increase and maybe the gig could then rank higher.