I have installed about a dozen Artix LXQT isos using different init systems without a problem. The last few installs were using dinit, again without a problem. Today I downloaded a new to me version of the dinit iso, artix-lxqt-dinit-20250407-x86_64.iso. SHA256 hash checked. Installed on a computer that previously had been running Artix runit without a problem. Installation completed normally.
New install booted fine, but nothing plugged into the USB ports were recognized by PCmanFM-Qt. On the terminal, lsusb showed all of the USB devices properly. df did not show USB mounted devices.
Comparing xdg related packages to another Artix dinit install showed the same packages installed, except xdg-dbus-proxy was missing on the new install. I installed this from the pacman repository, rebooted the computer, and the USB devices now display normally.
I post this to help anyone else who might run into this problem.
We put xdg-dbus-proxy in the LXQt default package list, latest weekly ISO should be fine.