rt-ac86u no open ports from wan

Hi! My configuration: WAN/Internet access Cisco EPC3928S router, NAT, all ports forwarded. RT-AC86U with Merlin FW 384.11_2, connected to above Cisco on LAN port . All devices on a local network can access Internet and can SSH to RT-AC86U or its WEB GUI. For SSH I have my own key pair and...