Crontab not working, Nextcloud and Luma Oled

[Banger21]

Hello everyone, I have a problem with my luma oled 1106. I use a Raspberry Pi 4 8GB and a nextcloudpi image of version 28. I've been trying for 4 days that the display starts automatically via cronjob after the reboot. But to no avail.

But if I go to the path /home/pi/luma.examples/examples/luma.examples/examples/ and use the command sudo python3 sys_info_extended.py --display sh1106, the display also works for the time I'm connected to Putty.

of my crontabs looks like this: @reboot python /home/pi/luma.examples/examples/luma.examples/sys_info_extended.py --display sh1106
Or @reboot python /home/pi/ssd1306/examples/luma.examples/examples/sys_info_extended.py (times with sudo python3)

I've tried running the cron as pi user, root and www-data but it doesn't work

I have another Luma Oled to another Raspberry Pi 4 8GB with openmediavault and the whole thing works without any problems. For me, it means that through the nextcloud image, because there is something in the way to make it work. I had thought about writing a script but unfortunately I am not familiar with it and then starting the script via cronjob.

I'm really frustrated and I don't know what to do, maybe someone here has an idea that will help me.

Sorry for my bad English, my national language is German.

I'm looking forward to your help