There is a device tree for R4S only, no dedicated one for R4SE, same with U-Boot, so unless both explicitly have eMMC included, it is expected that this does not work, at least not to boot from. I’m not sure about other minor hardware differences between R4S and R4SE, so there may be other subtile issues.
However, it does boot at first, including network, obviously, so it should be able to continue work after reboot.
This indeed sounds like it hangs on shutdown. The SYS LED should switch off for some seconds during early boot stage.
The WAN LED works for you already? I did just yesterday enable it in our image build scripts and a patch in DietPi dev branch. With our current image, both Ethernet LEDs shouldn’t do anything. Or do you mean the ones at the back side, below the Ethernet ports?
And btw, at least on my R4S, eth0 (which is configured on first boot and by dietpi-config) is the “LAN” port, not the “WAN” port.
Did you use our latest image, from the link above? Could you try to go through first boot and setup again, but not reboot, instead:
sync
dmesg -l emerg,alert,crit,err
cat /etc/network/interfaces
To check whether there are kernel errors and network is configured as expected, at best DHCP on eth0 (“LAN” port), the default on first boot, to rule out that it’s just a network issue.
Do you have a UART adapter, to monitor late shutdown and early boot logs on serial console?