https://stock.adobe.com/contributor/207882786/christopherThere's your portfolio link (you posted to the contributor side which no one but you can see)
I think you haven't ordered your keywords with the first 7 (or 5, I forget which) being the most important. That's going to mean lower positioning in searches for your most sales-worthy keywords. If you search here you can see Mat Hayward confirm that this does matter for searches (i.e. it's not a contributor-concocted conspiracy theory)
The subject matter of your images isn't going to be high selling, especially in the fall busy season, so that and the small size of your portfolio at Adobe is probably also a factor.
Some of the search positioning is luck of the draw - if things get seen and sold when they're relatively new, they get better search position thereafter, which in turn helps sales. Possibly you were luckier on the other sites when the initial uploads occurred?
Or none of the above

As a general keywording guide, I'd not rely on words in the title being searchable - they are on Adobe Stock, but not all sites search them, so you loose out.