It seems like your AP is operating in bridge mode (or probably half-bridged, assuming you can reach the appliance WUI from its wired interfaces). In this mode, the AP is unable to route packets (IP based routing on the network layer 3) and can only forward them directly to the MAC addresses of wireless devices (layer 2 data-link). This is why you’re unable to access the AP’s admin page from your green network. Additionally, being in bridge mode typically restricts the device to connecting only two networks, which could be the cause of your issues with wired connections not being able to access the internet.
Edit: this message is my reply to another member of the community with a different problem. The AP is set in routing mode. Just to give you some more context on the trade-off between setting the AP in routing or bridged mode.