I have an AX86U-Pro and attached an AC68U to one of the LAN ports to use as an isolated net for IOT's. It works well. But I cannot figure out how to sign in to the AC68U from my desktop connected to the AX86U-Pro. The only way I can access the AC86 is by connecting directly to it with an Ethernet cable. Neither the IP set on the AC68U (18.104.22.168) nor the address of the router assigned by the AX86 work. Any guidance would be greatly appreciated.