sadly i dont have logs :/
the command works manually but if i set crontab -e for every few hours and wait a few days no update is applied / upgraded
and this is the first Thread showing up in the websearch results
so i thought it would be nice if its up to date
The file looks valid but pveupgrade doesn't seem to be designed to run non-interactively. I think it can ask for confirmation, for example.
Have you tried checking the journal to see what it says around that time?
I'd set it to run every minute and then follow the logs via journalctl -f. You can also pipe (append) the output into a logfile pveupdate is already scheduled to run via pve-daily-update.timer.
If you really want to do this use something like this