The first-run command should create a new tvheadend configuration including an admin account with no name and no password, but it aborts (-A) too early without saving the files. I reported the bug here: https://tvheadend.org/issues/6140
This workaround fixes the problem by removing the tvheadend -A switch and replacing it with a 10s delay and a kill signal. That should be enough even for slow routers to generate and save the configuration. It is meant to be a temporary fix until tvheadend bug is resolved.
Signed-off-by: Marius Dinu <m95d+git@psihoexpert.ro>