So this is issue has been following me through all my HASS installations (RPI, NUC, docker, systemd): Home Assistant does not handle connection failures when starting up.
Meaning that if influxdb or deconz start later than HASS, it will never reconnect as setup fails, so I'll have to manually check HASS whenever I reboot so that it started up correctly.
I do have a UPS and the server should never restart by itself, but still, I do want to leave HASS unattended after I configure it.
Most of the solutions I've found stops HASS from starting if dependencies are not available.
(the best solution was to combine docker-compose depends_on and systemd - but recreating the container on start