I have same issue on AX86U.
WAN connection is PPPoE and my ISP changes IP around 4am every morning, only using IPv4. Yesterday I noticed I cannot connect to NAS, though I forgot to forward ports after reset, but in the end I noticed IP on my DDNS domain wasn't updated. After I manually updated it worked again until this morning when IP changed again.
I'm using custom DDNS script, this is script code:
Code:
#!/bin/sh
# register a subdomain at https://www.duckdns.org/ to get your token
SUBDOMAIN="xxx"
TOKEN="xxx"
# no modification below needed
curl --silent "https://www.duckdns.org/update?domains=$SUBDOMAIN&token=$TOKEN&ip=$1" >/dev/null 2>&1
if [ $? -eq 0 ];
then
/sbin/ddns_custom_updated 1
else
/sbin/ddns_custom_updated 0
fi