Hello,
Thank you for provided screenshots.
As you might see, reboot are done by the ping reboot feature, which from time to time checks if the IP address (in your case 192.168.66.1) is reachable or not. If not - device will automatically reboot itself.
If you want to use ping reboot, I would recommend using public IP instead of local IP address, for example 8.8.8.8 is a good IP to use.
Moreover, ping reboot is used to check what ever router/gateway has internet access or not. If there is no internet access - device will perfome selected action, for example - reboot.
Best regards,