tracert not display the correct hop

[sean3]

we have 4 fortigates run v7.0.14 build0601 (Mature), one per each WAN site.

I tracert from a host behind one fortigate of site A, to a target host behind the fortigate of site B

C:\Users\ADM-name>tracert 10.80.131.12

Tracing route to hsot.company.com [10.80.131.12]
over a maximum of 30 hops:

1 199 ms <1 ms 26 ms 10.250.14.1
2 <1 ms <1 ms <1 ms 172.29.7.22
3 216 ms 216 ms 216 ms 10.250.29.15 (Y)
4 243 ms 242 ms 242 ms 172.16.10.17
5 242 ms 242 ms 242 ms host.company.com [10.80.131.12]

the 3rd hop is not the desired one by SD-WAN. We have 2 tunnel-type interface (let's say X and Y) in SD-WAN outgoing interface bundle. The tracert shows Y but actually X is the selected outgoing interface.

and if we do diag sniffer with interface X, it has traffic result, and no traffic result if diag sniffer with interface Y, meaning traffic is going through the correct interface.

what is the logical of fortigate replying tracert request? Why it is like this?

[AlexC-FTNT]

I think you can check this explanation here:
https://community.fortinet.com/t5/FortiGate/Technical-Note-tracert-traceroute-behavior-over-IPsec-VP...
It has to do with the lowest interface index as interfaces are defined in FortiGate.

Edit: wrong link posted before