Autostart files do not work in DE/WM

Some time ago I installed FreeBSD 10.3-RELEASE on two of my laptops and proceeded to x11-wm/openbox setup shortly after. Surprisingly, on neither of them would .config/openbox/autostart work. In the past it was enough to copy the default autostart from /usr/local/etc/xdg/openbox/autostart and perhaps do chmod +x autostart. Generating a fresh autostart also doesn't work.

Even more surprisingly, the same problem occurs with x11-wm/pekwm and x11/lumina, but only on 10.3-RELEASE. Somehow 11-CURRENT works alright.

I tried changing the ports tree from quarterly to latest and re-installing everything - still no go.

For now I circumvented the problem by adding the necessary lines to .xinitrc. Below my Openbox autostart:
nitrogen --restore &
(sleep 1s && tint2) &
(sleep 2s && volumeicon) &

Does anyone experience similar problems?