It seems that I cannot save any of the settings.
Everything works after setting it up via the Gl.Inet interface, but a reboot clears all of the settings. Going into the native OpenWrt interface shows that there are 40+ unsaved settings and clicking apply does not actually save them. The screen appears to be saving, but then still shows the same number of unsaved settings up in the corner.
Since the settings cannot be saved, there is no password and SSH is running on the unspecified interface, so I cannot actually connect this up to the internet until that gets sorted.
Looking forward to some advice.