Istio canary deployment issue

Dear community,
I’ve tried Istio as a tool for canary release for my Bachelor thesis. It works fine, but whenever I try to get version 2, it routes me back to version 1. The issue is already described at StackOverflow. ( kubernetes - Istio canary release issue - Stack Overflow ).

I would be very grateful for any help for this issue. StackOverflow community does not take much care about this issue, so I try this official Istio community to help me.