Ah, I stand humbly corrected. My node’s uptime is over 300 days now, so I clearly forgot what happened at last reboot.
(Although I could have sworn the nodes didn’t start automagically!)
I will delete my erroneous post, then, so as to not mislead anyone and to try and save whatever little is left of my self respect
The node could not be started, if docker daemon not started after boot. By default it starts own service on first call of any command. You need to enable it to being started automatically: Post-installation steps for Linux | Docker Documentation