Wetek Core with LibreElec v7.0.2 on NAND restarts by itself from time to time

Hi,
The title says it all: I have installed the latest version 7.0.2 of LibreElec on my new Wetek Core (installed on NAND) and everything works perfectly.
However, when shut down, the device restarts by itself from time to time.
Is there any Wake On Lan feature or so which could cause this? Otherwise, any clue?
Thanks in advance for any help.
Kind regards.
Greg