Let me re-explain.
- Your OpenVPN Client profile does not have IPv6 enabled. it uses the parameter
proto udp6 to enable it.
- The VPN Client feature on the AXT1800 does not yet support IPv6.
So you should disable IPv6 on the AXT1800 and then retest traceroute google.com
We now need to verify that when the AXT1800 accesses the Internet, the packets are correctly forwarded to the RT-AX86U.