I have several orangepi with this problem. Looking better I saw that the systemd was updated and after that the problem started. From version 229-4ubuntu21.2 to 229-4ubuntu21.9.
I also found this to follow: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1804603
I'm using ARMBIAN 5.38 stable Ubuntu 16.04.4 LTS 3.4.113-sun8i.