What will be the naming convention and resolution(dimensions) for screenshots?

Two months ago, I’ve uploaded the product in which screenshots are of dimensions(1080x1920) and that product is approved by CodeCanyon. Unfortunately this time they are rejecting my product because of “The screenshots are still too big” and “Make sure you are following the naming conventions for screenshots.”

I’m really stuck in this issue I found out some answers in which people said to make width of 614px but I believe that width will make screenshot too smaller.

These rules must be relatively new, but per the Help Center:

Preview Image Set

You can provide additional preview images. They must be JPGs no larger than 900x900px , and named in the order that you want them to appear using the following format:

01_preview1.jpg, 02_preview2.jpg, 03_closeup.jpg .

Create a .zip folder containing your additional preview images.

Really appreciate your reply. Just one thing I want to clear is that Envato calling screenshots as “Preview Image Set” ?

Yes, the preview image set is referring to this field on the upload page: