Packets routing is normal except tracing routes an IP address outside NAT. My diagram:
Traceroute result is normal for IP address inside NAT. But timeout two hop for IP address outside NAT:
Packet Sniffer of outside IP (traceroute). I found packets was routed to wrong interface. Packets started to loop until TTL to 0.
However, routing for data traffic is normal. The problem happens on traceroute only.
Add another screenshot.
Packet Sniffer of inside IP (traceroute) is normal.
I solved problem. It’s misconfiguration.
Connection mark of IP address A to B not only marks the session of A and B. besides that, connection mark also mark all related traffic. For example, ICMP control traffic from intermediate route between A and B. I missed it.