Just recently XDG Portals to get video sharing working. It just kept using the GTK fallbacks instead of KDE as I configured it, but it used the correct ones when starting from the terminal.
Eventually I figured out I had set an env override for XDG_CURRENT_DESKTOP="sway"
in my user systemd environment, because that’s what I used previously.
*nix
is more likely to be a glob, therefore an accurate version would be*n?x
Edit: global -> glob dang autocorrect