sudo reboot does not work after a program has crashed

I am troubleshooting an issue with tvheadend. It crashes, but if it has crashed and i try a “sudo reboot” the entire box freezes. Does not matter if I do this over SSH or on the console. What happens there is that a text screen with “OpenSuse login” flashes briefly and then the screen goes blank. The box does not reboot. Any ideas why?

Have you tried e.g.:

ssh root@<hostname>  systemctl reboot

No. Will do next time. Thanks.

Did not help, sorry