[XDG-Portal-KDE] When saving files, files with a different file extension inside the target folder appear briefly before disappearing

Almost filled a bug with wishlist priority, but there was a comment there about trying to discuss things here if not a bug, so I came.

I just wanted to point this, is a minor thing, but it makes some difference to to Plasma’s visual polish, I think.

I had the impression, and I may be remembering wrong, that on Plasma 5 this didn’t happened or it happened to a lesser degree that was unnoticeable, but since Plasma 6 it became very evident.

When you’re browsing the net and find a file you want to download, you click on it and the file saver portal opens. By default if filters the files that are inside the folder and show only the files that share the save extension as the file you clicked to save.
But there’s a lag in this filtering process.
First all files on that folder are shown, then the filter finishes the job and hides all files with a different extension. Example, you want to save a JPG to a folder that has a mix of JPG and PNG files. First you’ll see the folder with all it’s JPG and PNG files, then a moment latter the PNG files will disappear.

Is about this lag that I want to talk about, is it possible to get rid of it? Because visually is ugly and a bit annoying.

I image if the file saver portal could do the filtering work behind the scenes before showing the contents of the folder, to already open with the files filtered and in the example I gave already open the folder showing only the JPG files, same as the file you’re saving.