Comment # 19 on bug 1210065 from Finkenbinder

I am having a lot of trouble with this bug. It keeps me from loading a systemd
user service that does some D-Bus stuff and shows a zenity dialog window. I
thought I was doing something wrong until I found all these different bug
reports about xdg-desktop-portal-gnome. 

The problem has been affecting me on multiple distros, but it's been
particularly problematic on openSUSE Tumbleweed with the KDE desktop. 

Doesn't seem like there is any good solution other than uninstalling
xdg-desktop-portal-gnome, or masking the service, but those solutions may cause
issues with logging into GNOME on the same system. 

This seems to have been at least partially fixed on Ubuntu and Fedora at this
point. 

The fact that there's no apparent action on this is unfortunate.