It’s likely related to the GTK file picker.
But now I wonder why my own Xfce system does not face this issue? Fully updated, just as yours and the other poster’s.
And just for kicks, no issues under KDE either (though Chromium detects the environment and uses KDialog under KDE, rather than GTK file picker.)
I’m thinking this is more specific to the GTK file picker (and/or a related dependency)