I have installed OpenWRT 18.06 on a RT-n16.
In Luci I've gone to networks -> Interfaces -> lan and changed the protocol to dhcp.
I then clicked save and apply.
The router reboots but still has 192.168.1.1 as the IP address. In Luci the settings have reverted to static ip.
My DHCP server says it's allocated 192.168.8.98 to the router.
It appears to be acknowledging the change but then reverting back to default for some reason.
I have tried power cycling and resetting, but the same behavior continues.
Please stay on the interface page until your changes has been applied. If you see (by default after 30s) such dialogue, please continue with "Apply unchecked" to safe your changes permanent.