Set default application to start on save/open file dialog

I am using i3wm on an up-to-date arch installation, and I would love to know how to change the application to open for the save/open file dialog. **How to reproduce** * If I open okular and select "Open File" I am greeted by an ugly file manager * If I click "save PDF" in chromium the same app opens up **What I have tried** * set the default in exo-preferred-applications * set manually in every mime config file I could find on my machine (inode/directory=Nautilus.desktop;) * and a bunch of other fixes I found online * xdg-open and mimeo are opening the right app when opening a directory I also have gnome installed on my PC, and when starting up chrome on this desktop manager it opens nautilus, so I think it might be handled by the desktop/window manager, thus i3 in my case.