Development board does not reboot

Hello

When executing the command line “sudo reboot”, I don’t have any message telling me that the system will start again.
It just shuts down, but the LED of the board is still on, as well as keyboard and mouse; but the system does not start, it does not connect to the network, and the screen is inactive.

I have to unplug the power supply to start again.

Has anyone experienced a similar problem?
Any help to solve my problem would be grateful.

Thank you very much
Best regards
Sarah