Add device on samsung smartthings

hi there,
i'm trying to add some samsung devices (like washer or air conditioner) on the smartthings app.
i've tried to connect this things with my phone (android) acting like a router and all went well (so devices works well).
when i try to do the same things with my openwrt router (raspberry pi4) there's something wrong.
i use a netgear wax214 access point, with WPA2-AES key (short SSID and only letters password). Maybe some firewall setting? thanks for help...

this is the log, while trying to connect:

root@OpenWrt:~# logread -f
Mon Mar 18 15:51:16 2024 daemon.info dnsmasq-dhcp[1]: DHCPDISCOVER(br-lan) 68:3a:48:0c:98:eb
Mon Mar 18 15:51:16 2024 daemon.info dnsmasq-dhcp[1]: DHCPOFFER(br-lan) 192.168.1.135 68:3a:48:0c:98:eb
Mon Mar 18 15:51:16 2024 daemon.info dnsmasq-dhcp[1]: DHCPREQUEST(br-lan) 192.168.1.135 68:3a:48:0c:98:eb
Mon Mar 18 15:51:16 2024 daemon.info dnsmasq-dhcp[1]: DHCPACK(br-lan) 192.168.1.135 68:3a:48:0c:98:eb Samsung-Room-AC
Mon Mar 18 15:52:58 2024 kern.warn kernel: [ 5171.543862] [nat46] Could not translate v4->v6

how can i solve "Could not translate v4->v6"?