@Barney I see same problem but I read the doc here https://docs.gl-inet.com/en/3/setup/mini_router/internet/
It say in this doc
It works in WISP (Wireless Internet Service Provider) mode by default, which means that the router will create its own subnet and act as a firewall to protect you from the public network.
I maybe agree this working. Problem for me is wifi no exist in air for me so really I not sure but when I look at interface it say different subnet for WAN and LAN.
But I agree with you this would be better if default was not hidden. @alzhao maybe should know two peoples thinks this. If you hide defaults you have somethings like a Mac computer and that is most terrible.