Thanks for your continued replies.
I tried updating to Bolt 3.4.6 again with the following config block as suggested:
And I have the following crontab item:
* * * * * /var/www/app/nut cron
However, that does not seem to trigger the timed publish. I also tried running
/var/www/app/nut cron manually after the scheduled publish time, but that did not work either. Clearing the cache manually also did not trigger the timed publish if the config setting
use_cron is set to true, but otherwise it would.