@BeAware Oh no. You mean, "Did you turn if off, and then back on" is not the universal fix, after all?
Did you do "systemctl status sharkey" to see if the service is running? If so, then it's probably a different issue. Also do a "journalctl -u sharkey" to check the service logs?
I'm not a Linux expert, but these are two things I'd do to start off with.