From a UART console (or ssh or luci) sending a reboot command fails to actually reboot the device. Instead it just sits for a minute or two before returning the CLI prompt again.
Repeating /sbin/reboot no change.
I can trigger an instant reboot with
echo b > /proc/sysrq-trigger
Might be something in the OpenWRT UBoot versus the FriendlyWRT UBoot?